What is wood sawing? Sawing wood, preparing for work

14.07.2019 -

The process of sawing wood produces beams, whetstones and planks. Wood is cut with hand or electric saws.

The saw is a tape or disk with cut teeth (cutters) (Fig. 8). Each saw tooth has three cutting edges: one front short and two side (Fig. 8, A). U rip saw Wood teeth with a short cutting edge cut the wood fibers, and with the side teeth they separate them from each other in direction. The teeth of these saws have a straight edge and are shaped like a triangle, so they can only be sawed in one direction. The teeth cross cutting saw have a shape isosceles triangle and double-sided sharpening, so they can be sawed in both directions. The short cutting edge of these saws separates the wood fibers, while the side cutting edges cut them. The saw teeth have the following parameters: step- the distance between two adjacent vertices and height- the distance between the base and the top of the tooth. A depression is used to remove sawdust generated during the sawing process.

In addition to saws for longitudinal and cross cutting, there are also carpentry saws. The teeth of these saws are designed so that they can cut wood lengthwise and crosswise. They are an isosceles triangle with a right angle directed towards the sawing. The dimensions of the cutting angles of the teeth are the average value between the angles adopted for saw teeth for longitudinal and transverse cutting.

Hand saws. Hand saws can be untensioned - transverse two-handed, knife saws (hacksaws) with a free blade, and tensioned - bow saws.

Two-handed cross saws used for transverse cutting of beams, bars, boards (Fig. 8, b). The teeth have the shape of an isosceles triangle, the sharpening is oblique.

Two workers operate a two-handed crosscut saw. The wood is placed on a stand (table, sawhorse) and the cut location is marked on which the saw is installed. You need to start cutting with the middle of the saw, and when the middle teeth go deeper into the wood, gradually

Rice. 8. Hand saws:

A- saw elements, b- two-handed transverse, V- wide transverse hacksaw, G- narrow hacksaw, d- a hacksaw with a butt, e- reward, w - bow saw; / - front short cutting edge, 2 - front edge, 3 - side cutting edges, 4 - line of the base of the saw teeth, 5 - saw blade, 6 - the top of the tooth, 7 - the sinus or cavity of the saw tooth, 8 - pen, 9 - racks, 10 - bowstring, // - muzzle, 12 - twist

bring the scope of the saw to its entire length. They work with a saw like this: alternately, one of the workers smoothly pulls the saw towards him, and the other gives it to the person pulling it freely, while those working with their free hands (usually their left) support the material being cut. When sawing, do not press the saw too hard, as it may get stuck in the cut. The saw must be well sharpened and set correctly.

Knife saws(hacksaws) are wide, narrow and with a back. A wide hacksaw (Fig. 8, V) used for manual sawing of wood and wood materials when performing carpentry and carpentry work. Hacksaws are made for transverse (type /), longitudinal (type 2) sawing of wood and universal (type 3) (GOST 26215-84). They may have replaceable blades.

The teeth of hacksaws must be sharpened and set apart, and the tooth must be set apart over at least 2/3 of its height from the top. Hacksaw type teeth 2 executions / must have direct sharpening only on the front edge of the tooth.

The teeth are set by alternately bending them in different directions by the following amount: for teeth with a pitch of up to 3 mm - 0.1...0.3 mm on one side; 3 mm or more - 0.3...0.6 mm on one side. The hacksaw blade must have a protective coating.

Using a narrow hacksaw (Fig. 8, G) saw thin lumber, cut curved parts and make through cuts.

A hacksaw with a butt (Fig. 8, d) used for making shallow cuts, miter cuts and sawing small pieces of wood, as well as for fitting joints. The upper part of the saw has a thickening. Handle thickness 22 mm; blade thickness up to 0.8 mm. The teeth are shaped like a right triangle. Since the canvas has a small thickness, a butt is riveted in the upper part to give it rigidity.

Hacksaw-reward (Fig. 8, e) used for blind sawing of grooves for keys, as well as for sawing out narrow grooves. It has a thickness of 0.4...0.7 mm.

Bow saw(Fig. 8, and) used for longitudinal and cross cutting of wood. A saw is a wooden machine (beam) with a blade stretched on it. The ends of the saw blade are inserted into the handles of the racks and secured on pins, the racks are connected with a middle, and the opposite ends of the racks are tied with a bowstring, tensioned with a twist. The machine is made of hardwood, the bowstring is made of twisted linen or hemp cord with a diameter of 3 mm. The wooden elements of the bow saw are impregnated with drying oil, sanded and coated with light nitro varnish.

Due to the fact that the blade of a bow saw is tensioned, it is made longer and thinner than that of a hacksaw, thanks to which it can be used to cut in full swing, and the cut is thinner and of better quality.

Bow saws can be swing saws, transverse saws, circular saws, or tenon saws.

Swing saws have a blade with a width of 45...55 and a thickness of 0.4...0.7 mm, a tooth pitch of 5 mm, and a tooth sharpening angle of 40...50°. The teeth are sharpened straight. Blade length 780...800 mm. These saws are used for longitudinal cutting of wood.

Cross-cut saws with a blade width of 20...25 and a thickness of 0.4...0.7 mm, tooth pitch 4...5 mm, tooth sharpening angle 65...80°. The teeth have the shape of an isosceles triangle, the sharpening is oblique. Blade length 750...800 mm.

Circular saws are used for curved figure sawing. They have a blade up to 500 mm long and 4...15 mm wide, straight-ground teeth with a pitch of 2...4 mm, a sharpening angle of 50...60°. The thickness of the saw blade is no more than 1 mm, so a narrow cut is obtained.

Tenon saws are used for cutting out tenons and lugs. They have a blade with a width of 40...50 mm, a thickness of 0.4...

Rice. 9. Jointing the tops of the saw teeth:

A- in a special block, b- on the workbench; I- file, 2 - block, 3 - saw, 4 - workbench

0.5 mm, rectangular teeth with a pitch of 3...4 mm and a sharpening angle of 80...85 0. The saw has a length of 600...700 mm.

At the end of sawing, the string should be loosened somewhat so as not to stretch the saw blade. The handles should fit tightly into the racks and turn with little effort. In addition, to avoid stretching the bowstring when not in use, you should loosen the twist a little.

Preparing hand saws for work consists of jointing, setting and sharpening saws. First, the saws must be thoroughly cleaned of resin, adhering sawdust, and rust, and washed in kerosene. If the surfaces of the canvases have unevenness, they are straightened with a hammer on a flat metal plate. Then they begin jointing - leveling the tops of the saw teeth, since they must be at the same height. In a wooden block (Fig. 9, a) insert a file, after which the block with the file is put on the saw and moved along the blade, aligning the tops of the teeth.

There is another way to align the tops of the saw teeth. A board is strengthened in the workbench (Fig. 9, b), into the slot of which a file is first inserted, and then the saw blade with the teeth down and, moving the saw along the file, the tops of the teeth are aligned. It is necessary to align the tops of the teeth periodically, otherwise they will unevenly participate in sawing. The quality of jointing is checked by applying a ruler to the tops of the teeth. If the tops of the teeth are tightly adjacent to the edge of the ruler, the jointing is performed correctly.

During the sawing process, the saw blade rubs against the walls of the board being cut and is clamped in the cut. To avoid pinching the saw blade in the cut, the teeth must be set apart. The spread of saw teeth consists of bending them alternately: even teeth in one direction, and odd teeth in the other. When spreading the teeth, you need to bend not the entire tooth to the side, but only its upper part at approximately a height of 2/3 from the top.

When sawing hardwood, the teeth are set apart by 0.25...0.5 mm per side, and softwood - by 0.5...0.7 mm. We must strictly

Rice. 10. Tool for setting and checking saw tooth set:

A- simple setting with stops, b-d template for checking the correct setting of the saw teeth, V- universal" wiring, G- indicator water meter type RI; / - saw, 2 - sample, 3 - lever, 4 - plate, 5 - adjusting screws, b - hinged adjuster for the amount of adjustment, 7 - scale, 8 - screw with stop, 9 - spring, 10 - supporting surface, // - indicator

observe the size of the spread, since with a wide spread the cut turns out to be large and uneven.

The teeth of hand saws are set as follows (Fig. 10, A). The saw blade is tightly clamped in a vice, and then the teeth are bent alternately in one direction or the other. You need to spread the saw teeth evenly, without using much effort or sudden movements, as otherwise you can break the tooth. In addition to the usual, universal wiring is used (Fig. 10, V).

The correct alignment of the saw teeth is checked with a template (Fig. 10, b), applying it to the saw blade clamped in a vice. The even teeth are checked first, then the odd ones. Incorrectly bent teeth must be corrected.

The correctness of saw alignment can be checked more accurately with an indicator RI type alignment meter (Fig. 10, G). When measuring, the spread meter is pressed tightly against the saw blade with its supporting surface, and the tip of the indicator is placed opposite the top of the tooth being monitored. The amount of separation is determined by the deviation of the indicator arrow.

The next operation is sharpening the saw teeth with double and single cut files. According to their shape, files are divided into triangular, rhombic and flat. Hand saws are usually sharpened with triangular or diamond files.

When sharpening, the saw blade is clamped in a vice mounted on a workbench. The file is pressed against the tooth when moving away from you, and when returning it is slightly raised so that it does not touch the saw. You should not press the file tightly against the tooth, as this will heat up the file, which will lead to a decrease in the strength of the saw teeth. Straight saw teeth for rip cutting

Rice. 11. Sharpening saws with files:

A- location of the pilot point for direct sharpening, b- the same for oblique sharpening, V- sharpening a bow saw mounted in a vice, G- placed in a wooden block

sharpen on one side, and the file should be held perpendicular to the saw blade.

Saws for cross-cutting wood have an oblique sharpening, so their teeth are sharpened with a triangular file, which is held at an angle of 60...70°. These saws have teeth that are sharpened one at a time. Having sharpened the teeth on one side, turn the saw towards you with the other side and, securing it in a vice, sharpen the remaining teeth.

Bow saws are sharpened with triangular files, which are selected according to the size of the saw teeth. Sharpened saws should not have burrs, blue marks or other defects. Burrs are removed with a finely cut (velvet) file. Techniques for manually sharpening saws are shown in Fig. 11.

Hand saw techniques are as follows. To operate, the saw blade in relation to the machine (beam) is set at an angle of 30°, while the saw blade must be straight, without distortions and well tensioned. The correct installation of the saw is checked as follows: hold the centerpiece with your left hand, and the handle with your right hand and look at the saw blade with one eye. If the saw blade is installed correctly, it will look like a stretched thread (Fig. 12, A), and if it's wrong,

Rice. 12. Installation of bow saws:

A- the saw is installed correctly, b- the saw is skewed

then the twisted end will be thicker (Fig. 12, b). Correct the position of the saw blade by turning the handle.

When longitudinal sawing, a board or block is placed on a workbench or table so that the sawn part protrudes outward, that is, hangs over the workbench board, and is secured with a clamp. Then mark the cutting line with a pencil and ruler or thicknesser. The cutting line can be marked with the blade of a sharp chisel, which creates a slot in the form of a mark, clearly visible on the surface of the wood.

When sawing wood, the saw is directed in such a way that it does not leave the intended cutting line and does not become pinched in the cut, moves freely and easily, does not warp in the cut, but moves smoothly without swaying. If the saw blade is skewed, it will become pinched in the cut or it will be difficult to move due to friction, heat up and lose its strength properties.

During the sawing process right hand hold the saw by the stand, and support the board being cut with the left hand. In this case, the foot of the left foot should be parallel to the workbench, and the right one should be at an angle of 70...80° to the foot of the left foot.

When sawing (Fig. 13, A) make a “sweeping” motion, press the saw to the bottom of the cut when moving down and move it slightly to the side when moving up (idling). You need to cut smoothly, without sudden movements, strong pressure and without distortions. When sawing longitudinally, short boards with markings are secured in a vice in a vertical position so that the mark is visible to the worker (Fig. 13, c). The saw is placed on the marking line and a shallow cut is made with a slow movement toward you, after which you can cut to the full swing of the saw. Sawing can also be done on a block (Fig. 13, G).

When sawing, you need to monitor the quality of the sawn surface. A rough, rough surface is obtained if wood is cut with a saw with large and incorrectly spaced teeth, as well as when working with a poorly sharpened saw. Non-

Rice. 13. Longitudinal cutting:

A- boards laid on a workbench, b- position of the legs of the worker during longitudinal

sawing boards laid horizontally, V- sawing in a vertical position

boards, G- start of sawing along the block

Rice. 14. Transverse cutting of boards:

sawing boards, b - position of the worker during cross cutting (sawing)

Forward cutting of wood is also obtained with strong pressure from the saw and when deviating from the mark.

When cross-sawing boards and bars, the material is placed on a workbench or table so that the section to be sawn hangs from it, and according to the mark made in advance, a cut is made, holding the bow

Rice. 15. Cross-cutting with a bow saw in a sawing box (shtosslad)

hold the saw with your right hand by the stand above the handle, and support the material with your left (Fig. 14).

For precise transverse cutting of a board or block at a certain angle without markings, a sawing box is used (Fig. 15), in the side walls of which there are cuts made at a certain angle (45, 90°). When sawing, the material is supported with the left hand, and the right hand is taken by the saw stand and, directing it to the desired cut, the material is trimmed.

Mechanized sawing. Hand sawing cutting wood is a labor-intensive and low-productivity operation. The use of power tools for sawing wood increases labor productivity by 5...10 times, does not require much physical effort and improves the quality of work. For mechanized sawing, hand chain and electric circular saws are used.

Electric circular saws(IE-5102B, IE-5103, IE-5104, IE-5106, IE-5107) are used for longitudinal and transverse cutting of boards and bars of various types of wood. The IE-5107 electric saw is used for sawing boards and bars up to 65 mm thick along and across the grain. It can be used to cut wood at the desired angle (0...45 0). It consists of an electric motor, a single-stage gearbox, movable and fixed protective covers, a base, a saw blade, a wedging knife for sawing material, a handle with a switch and a filter for suppressing radio interference, a handle, and a power supply cable with a plug. It is safe to work with the saw, since the electric motor has double insulation (protection class P). The IE-5107 electric saw can also be used as a stationary machine by installing and securing it on a workbench.

Electric saws use flat circular saws (GOST 980-80) with a diameter of 160...200 mm and a thickness of 1.2...1.8 mm.

Electric circular saws are used to cut wood lengthwise (Fig. 16, a) and across (Fig. 16, a). b) fibers, select quarters

Rice. 16. Techniques for working with a circular saw: A- sawing wood along the grain; b- the same, across the fibers, V- quarter sample,

G- cutting of thorns, ridges

Rice. 17. Hand-held electric circular saw for wood:

1 - cable, 2 - main handle, 3 - electric motor, 4 - handle, 5 - panel (support plate), 6 - saw blade, 7 - guard (casing)

(Fig. 16, V) and cut off the thorns (Fig. 16, G). A general view of the circular saw is shown in Fig. 17.

rear and smoothly lower the saw onto the material being processed, mounted on a workbench or table. To avoid damage to the bench board, place defective material under the material being cut. The saw blade is installed in relation to the panels (slab) so that it protrudes to the depth of the cut.

You need to move the electric saw across the material straight and evenly, without jolts or distortions. When the saw moves quickly through the material, the saw blade may jam and the electric motor may overload, which will lead to its failure.

If the saw blade gets stuck in the material, it is necessary to move the power saw back a little and only after the saw blade is freed, when it reaches the desired rotation speed, can you continue sawing. If the saw blade stops when it jams, turn off the electric motor immediately. You need to move the saw across the material so that the saw blade is guided strictly along the markings. At the end of the work, the electric saw is disconnected from the network, cleaned with kerosene, lubricated and placed for storage in a special box.

Safety precautions. Before starting work, check the serviceability of the electric saw, the reliability of the insulation, the quality of sharpening of the saw blade, the strength of its attachment to the spindle, the correct installation and fastening of the panel (plate), and the serviceability of the casings. If, when using an electric saw, the saw blade “beats” (vibrates), you need to check the strength of its fastening, the sharpness of the saw teeth and determine whether the saw blade is bent. If the lower safety casing does not close well, check the tension of the spring and, if it is weakened, replace it with a more elastic one.

If the saw blade gets very hot during operation, check the sharpening of the teeth, their alignment and the correct installation of the saw blade (perpendicular to the spindle). If one of these defects is detected, work must be stopped, the saw blade replaced and correctly installed in place.

The power saw must be reliably grounded. It is safe to use an electric saw only in a dry room. In a damp, damp room, you can operate an electric saw with a voltage of 36 V.

You only need to work with a well-sharpened tool. The handles of hand saws must have a smooth surface, without burrs or knots. When carrying saws, to avoid injury, it is necessary to put covers on the blades. Hand saws should be stored in lockers. Saws should not be left on workbenches or tables. A worker who has thoroughly studied the safety rules may be allowed to work with electric saws.

When sawing, beams, whetstones, and boards are obtained. Wood is cut with hand or electric saws.

A saw is a band or disk with teeth (cutters) cut on it. Each tooth (Fig. 8, a) of the saw has three cutting edges - one short front and two side ones. In saws for longitudinal cutting of wood, the teeth with a short cutting edge cut the wood fibers, and with the side teeth they separate them from each other in direction. The teeth of these saws are straight-sharpened and shaped like a triangle, so they can only saw in one direction. The teeth of cross-cut saws have the shape of an isosceles triangle and are sharpened on both sides, so they can be sawed in both directions. These saws have a short cutting edge that separates the fibers and a side cutting edge that cuts them. The saw teeth have the following parameters: the distance between two adjacent vertices is the pitch, and the distance between the base 4 and the vertex 6 is the height of the tooth. To remove sawdust formed during the sawing process, depression 7 is used.

In addition to ripping and cross-cutting saws, there are also joiner's saws. The teeth of these saws are designed so that they can cut wood lengthwise and crosswise. They are an isosceles triangle with a right angle directed towards the sawing. The dimensions of the cutting angles of the teeth are average value between the angles adopted at the saw teeth for longitudinal and transverse cutting.

When working with a saw, sawdust is formed in the cut, which accumulates in the sinus. The volume of sawdust depends on the type of wood. Softwood is less resistant to cutting and more wood is removed with each sawing tooth than hardwood.

Hand saws. Hand saws can be untensioned - transverse two-handed and knife saws (hacksaws) and tensioned - bow saws.

Two-handed transverse saws (Fig. 8, b) are used for transverse cutting of beams, bars, and boards. The teeth have the shape of an isosceles triangle, the sharpening is oblique. Saws are produced in two versions. The sharpening angle for saws is 1-(40±2)°, and for saws it is 2-(45±2)°.

Transverse two hand saw two workers are working. The wood is placed on a stand (table, sawhorse), the cut location is marked, and then a saw is installed at this location. You need to start cutting with the middle of the saw, and when the middle teeth go deeper into the wood, gradually increase the span of the saw to its entire length. They work with a saw like this: in turn, each of the workers smoothly pulls the saw towards themselves, and the other worker gives it freely to the one pulling it, while those working with their free hands (usually their left) support the material being cut. When sawing, do not press the saw too hard, as it may get stuck in the cut. The saw must be well sharpened and set correctly.

Knife saws (hacksaws) are wide, narrow and with a back. A wide hacksaw (Fig. 8, c) is used for manual sawing of wood and wood materials when performing carpentry and carpentry work. Hacksaws are made for transverse (type 1), longitudinal (type 2) sawing of wood and universal (type 3) (GOST 26215-84). They may have replaceable blades.

The length of the cutting part of hacksaws of types 1 and 2 L = 250...650 mm, tooth pitch t = 2.5...6.5 mm, type 3 - L = 250...600 mm, tooth pitch t = 1. ..5 mm.

The blades of the hacksaws are made from high-quality steel, and the handles are made from 1st grade hardwood lumber, phenolic plastic, high-density polyethylene, and cast aluminum alloys. The teeth of hacksaws must be sharpened and set apart, and the tooth must be sharpened over at least 2/3 of its height from the top. The teeth of hacksaws type 2, execution 1 must have a straight sharpening only on the front edge of the tooth.

The teeth are set by alternately bending them in different directions by the following amount: for teeth with a pitch of up to 3 mm - 0.1... 0.3 mm on one side, for teeth with a pitch of 3 mm or more - 0.3... 0 .6 mm on one side. The hacksaw blade must have a protective coating.

Using a narrow hacksaw (Fig. 8, d) thin lumber is cut, curved parts are cut out and through cuts are made. The blade is made of cold-rolled tool steel, the handles are made of hardwood, impregnated with drying oil, sanded and varnished.

A hacksaw with a butt (Fig. 8, e) is used to make shallow cuts, miter cuts and sawing small pieces of wood, as well as when adjusting joints. The upper part of the saw has a thickening. Handle thickness 22 mm; blade thickness up to 0.8 mm. The teeth are shaped like a right triangle. Since the canvas has a small thickness, a butt is riveted in the upper part to give it rigidity. The hacksaw blade is made of thin-sheet tool steel, the handle is made of hardwood, coated with linseed oil, sanded and finished with varnish.

A hacksaw (Fig. 8, e) is used for blind sawing of grooves for keys, as well as for cutting out narrow grooves. It has a thickness of 0.4...0.7 mm.

A bow saw (Fig. 8, g) is used for longitudinal and transverse sawing of wood. It is a wooden machine (beam) with a saw blade 5 stretched on it. The ends of the saw blade are inserted into the handles of 8 racks and secured on pins, the racks 9 are connected by a middle 11, and the opposite ends of the racks are connected with a bowstring 10, tensioned by a twist 12. The machine is made of hardwood, the bowstring is made of twisted linen or hemp cord with a diameter of 3 mm.

Bow saws can be swing saws, transverse saws, circular saws, or tenon saws.

Swing saws have a blade with a width of 45...55, a thickness of 0.4...0.7 mm, a tooth pitch of 5 mm, and a tooth sharpening angle of 40...50°. The teeth are sharpened straight. Blade length 780...800 mm. These saws are used for longitudinal cutting of wood.

Cross-cut saws have a blade width of 20...25, thickness 0.4...0.7 mm, tooth pitch 4...5 mm, tooth sharpening angle 65...80°. The teeth have the shape of an isosceles triangle, the sharpening is oblique. Blade length 750...800 mm.

Circular saws are used for curved figure sawing. They have a blade up to 500 mm long, 4... 15 mm wide; teeth with straight sharpening and pitch 2...4 mm, sharpening angle 50...60°. The thickness of the saw blade is no more than 1 mm, so a narrow cut is obtained.

Tenon saws are used for cutting out tenons and lugs. They have a blade 40...50 mm wide, 0.4...0.5 mm thick, rectangular teeth with a pitch of 3...4 mm and a sharpening angle of 80...85°. The saw has a length of 600....700 mm.

Preparing hand saws for work. Preparation of saws consists of planing, setting and sharpening the saws. First, the saws must be thoroughly cleaned of resin, adhering sawdust, and rust, and washed in kerosene. If the surfaces of the canvases have unevenness, they are straightened with a hammer on a flat metal plate. Then they begin jointing - leveling the tops of the saw teeth, since they must be at the same height. File 1 is inserted into the wooden block (Fig. 9, a), after which the block with the file is put on saw 3 and moved along the blade, while aligning the tops of the teeth.

There is another way to align the tops of the saw teeth. In workbench 4, a board is strengthened (Fig. 9, b), into the slot of which a file is inserted, after which the saw blade is inserted into this slot with the teeth down and, moving the saw along the file, the tops of the teeth are aligned. It is necessary to align the tops of the teeth periodically, otherwise they will unevenly participate in sawing. The quality of jointing is checked by applying a ruler to the tops of the teeth. If the tops of the teeth are tightly adjacent to the edge of the ruler, the jointing is performed correctly.

During the sawing process, the saw blade rubs against the walls of the board being cut and is clamped in the cut. To avoid pinching the saw blade in the cut, the teeth must be set apart. The spread of saw teeth consists of bending them alternately: even teeth in one direction, and odd teeth in the other. When spreading the teeth, you need to bend not the entire tooth to the side, but only it top part approximately at a height of up to 2/3 from the base. When sawing hardwood, the teeth are set apart by 0.25...0.5 mm per side, and softwood - by 0.5...0.7 mm.

The teeth of hand saws are set apart (Fig. 10, a) as follows. The saw blade is tightly clamped in a vice, and then the teeth are bent alternately in one direction or the other. You need to spread the saw teeth evenly, without using much force. sudden movements, as otherwise you can break the tooth.

In addition to the usual one, a universal setting is used (Fig. 10, c), consisting of a lever 3, intended for bending the saw tooth, a plate 4, which regulates the width of the gap for the passage of the saw, and adjusting screws 5. At the top of the setting there is a scale 7, indicating the amount of setting , and a screw 8 with a stop, which regulates the height of the tooth being bent. Spring 9 serves to return lever 3 to its original position after compression of the wiring.

The correct alignment of the saw teeth is checked using template 2 (Fig. 10, b), applying it to saw blade 1, clamped in a vice. The even teeth are checked first, then the odd ones. Incorrectly bent teeth must be corrected.

The correctness of saw alignment can be checked more accurately with an indicator RI type alignment meter (Fig. 10, d). When measuring, the water meter is pressed tightly against the saw blade with its supporting surface, and the tip of the indicator is placed opposite the top of the tooth being monitored. The amount of separation is determined by the deviation of the indicator arrow.

When sharpening, the saw blade is clamped in a vice mounted on a workbench. The file is pressed against the tooth when moving it away from you, and when returning it is slightly raised so that it does not touch the saw. You should not press the file tightly against the tooth, as this will heat up the file, which will lead to a decrease in the strength of the saw teeth. Teeth with straight sharpening of saws for longitudinal cutting are sharpened on one side, and the file should be held perpendicular to the saw blade.

Saws for cross-cutting wood have an oblique sharpening, so their teeth are sharpened with a file, which is held at an angle of 60...70°. These saws have teeth that are sharpened one at a time. Having sharpened the teeth on one side, turn the saw towards you with the other side and, securing it in a vice, sharpen the remaining teeth.

Techniques for working with hand saws. To operate, the saw blade in relation to the machine (beam) is set at an angle of 30°, while the saw blade must be straight, without distortions and well tensioned. The correct installation of the saw is checked as follows: hold the centerpiece with your left hand, and the handle with your right hand and look at the saw blade with one eye. If the saw blade is installed correctly, it will look like a stretched thread (Fig. 12, a), and if incorrectly, then the twisted end will be thicker (Fig. 12, b). Correct the position of the saw blade by turning the handle.

When sawing, hold the saw by the stand with your right hand, and support the board being cut with your left hand, while the foot of the left foot should be parallel to the workbench, and the right one should be at an angle of 70... 80° to the foot of the left foot.

When sawing (Fig. 13, a) they make a “sweeping” motion, press the saw to the bottom of the cut when moving down and move it slightly to the side when moving up (idling). You need to cut smoothly, without sudden movements or strong pressure, and without distortions. When sawing longitudinally, short boards with markings are secured in a vice in a vertical position so that the mark is visible to the worker (Fig. 13, c). The saw is placed on the marking line and a shallow cut is made with a slow movement toward you, after which you can cut to the full swing of the saw.

Precise cuts are sometimes made “from the nail” or along a joint thumb(Fig. 13, d). The nail of the thumb of the left hand is placed exactly at the notch, after which the saw is slowly pulled towards itself close to the nail with light pressure on the wood, while the teeth go deeper and make a cut, then, moving away left hand, continue sawing in the middle of the blade, moving the saw not to full swing. Only after the saw has deepened into the cut do they saw in full swing. When sawing "from the nail" you need to be very careful. To avoid injuring your hand, keep your fingernail or knuckle above the teeth of the saw blade. Sawing on a block begins in approximately the same way (Fig. 13, d).

When cross-sawing boards or bars (Fig. 14), the material is placed on a workbench or table so that the section to be sawn hangs from it, and according to the mark made in advance, a cut is made, holding the bow saw with the right hand by the stand above the handle, and supporting the material with the left.

For precise transverse cutting of a board or block at a certain angle without markings, a sawing box is used (Fig. 15), in the side walls of which there are cuts made at a certain angle (45, 90°). When sawing, the material is supported with the left hand, and with the right hand, the saw is taken by the stand and, directing it to the desired cut, the material is trimmed.

Mechanized sawing. Manual sawing of wood is a labor-intensive and low-productivity operation. The use of power tools for sawing wood increases labor productivity by 5...10 times and does not require much physical effort. For mechanized sawing, hand chain and electric circular saws are used.

Electric chain saws (EP-K5M, EP-K6, K-5M) are designed for cross cutting of round timber, beams, and boards. The cutting tool in these saws is an endless saw chain driven by an electric motor through a gearbox. A saw chain is a set of individual links (teeth) connected by hinges. The EP-K6 saw has a working length of the cutting part of the saw of 445 mm, a chain speed of 5.4 m/s, a power of 1.7 kW, a voltage of 220 V, a current frequency of 200 Hz. Dimensions 438X305X573 mm, weight 8.8 kg.

Electric circular saws (IE-5102B, IE-5103, IE-5104, IE-5106, IE-5107) are used for longitudinal and transverse cutting of boards and bars of various types of wood. The IE-5107 electric saw is used for sawing boards and bars up to 65 mm thick along and across the fibers. It can be used to cut wood at the desired angle (0...450). It consists of an electric motor, a single-stage gearbox, movable and fixed protective covers, a base, a saw blade, a wedging knife for sawing material, a handle with a switch and a filter for suppressing radio interference, a handle, and a power supply cable with a plug. It is safe to work with the saw, since the electric motor has double insulation (protection class P). The IE-5107 electric saw can also be used as a stationary machine by installing and securing it on a workbench. Specifications circular electric saws are given in table. 1.

Electric saws use flat circular saws (GOST 980-80) with a diameter of 160...200 mm and a thickness of 1.2...1.8 mm.

Using circular electric saws, the wood is sawed along (Fig. 16, a) and across the fibers (Fig. 16.6), quarters are selected and tenons are cut (Fig. 16, c, d). General view circular saw is shown in Fig. 17.

Before starting work, you need to inspect the saw blade, check that the saw teeth are set correctly and sharpened, that there are no cracks on the blade, and that it is correctly seated on the spindle and secured with a nut. In addition, check the serviceability of the gearbox by turning the saw blade. If the saw blade rotates easily, the gearbox is working properly, and if the disk moves with difficulty, then, apparently, the lubricant in the gearbox has thickened. To dilute the lubricant, turn on the electric saw at idle speed for 1 minute. After checking the operation of the saw while idling, take the front handle of the electric saw with your left hand, and the rear handle with your right hand and smoothly lower the saw onto the material being processed, mounted on a workbench or table. To avoid damage to the bench board, place defective material under the material being cut. The saw blade is installed in relation to the panels (slab) so that it protrudes to the depth of the cut.

If the saw blade gets stuck in the material, it is necessary to move the power saw back a little and only after the saw blade is freed, when it reaches the desired rotation speed, can sawing continue. If the saw blade stops when it jams, turn off the electric motor immediately. You need to move the saw across the material so that the saw blade is guided strictly along the markings. At the end of the work, the electric saw is disconnected from the network, cleaned with kerosene, lubricated and placed for storage in a special box.

Safety precautions Before work, check the serviceability of the electric saw, the reliability of the insulation, the quality of sharpening of the saw blade, the strength of its attachment to the spindle, the correct installation and fastening of the panel (plate), and the serviceability of the casings. If, when using an electric saw, the saw blade “beats” (vibrates), you need to check the strength of its fastening, the sharpness of the saw teeth and determine whether the saw blade is bent. If the lower safety casing does not close well, check the tension of the spring and, if it is weakened, replace it with a more elastic one.

The power saw must be reliably grounded. It is safe to use an electric saw only in a dry room. In a damp, damp room, you can operate an electric saw with a voltage of 36 V.

You only need to work with a well-sharpened tool. The handles of hand saws must have a smooth surface, without burrs or knots. When transferring saw blades to avoid injury, it is necessary to wear covers. Hand saws should be stored in lockers. Saws should not be left on workbenches or tables. A worker who has thoroughly studied the safety rules may be allowed to work with electric saws.

Saw tooth shape for rip and cross cuts

Classification of types of sawing

Characteristics of the sawing process

Sawing is the process of dividing wood with a saw into voluminous, undeformed parts by turning the volume of wood between these parts into chips.

A saw is a multi-blade cutting tool that works in a closed cut. A kerf is a gap formed in wood when narrow shavings (sawdust) are cut with teeth. The cut has side walls and a bottom with which the blades (teeth) interact.

Sawing wood is classified according to several criteria.

Taking into account the dependence of the position of the saw plane in relation to the wood fibers, sawing is distinguished between longitudinal, transverse and mixed.

For longitudinal sawing the plane of the saw is parallel or approximately parallel to the grain of the wood. Sawmill frames, circular saws and band saws operate on the principle of longitudinal sawing, on which logs and beams are sawed into boards, lumber is cut in width or thickness in the longitudinal direction.

When cross cutting the plane of the saw is perpendicular or approximately perpendicular to the grain of the wood. Sawing is performed manually with cross-cut saws, hacksaws or on cross-cutting machines used for cutting logs into round logs, removing wood defects and wane areas from the ends of the lumber, as well as giving the lumber a given length and quality.

For mixed sawing the saw plane is located at an acute angle (10˚...80˚) to the direction of the fibers.

Taking into account the dependence on the type of saws used, they distinguish the following types sawing:

– longitudinal frame sawing, sawing with band, circular and jigsaws;

– cross-cutting with circular, chain and jigsaws;

– mixed sawing circular, band and jigsaws.

Taking into account the dependence on the number of simultaneously working saws in the machine, a distinction is made between individual and group cutting methods of lumber. Cutting logs and lumber with one saw is called individual cutting, and cutting with several saws is called group cutting.

For individual sawing logs are sawn into lumber with separate cuts on circular saws, band saws, vertical or horizontal machines. The cutting is carried out taking into account individual characteristics quality zones of each log. This cutting method is effective when sawing valuable wood, cutting large-diameter logs and logs with significant defects.

For group sawing sawmill frames, multi-saw circular saws and band saws, as well as milling and sawing machines are used.

Taking into account the dependence of the workpiece position relative to the center circular saw sawing is distinguished by the peripheral zone of the saw, middle zone and the central zone of the saw, as well as sawing with the upper and lower zone of the saw.

When working in the peripheral zone saws, the teeth of the saw protrude above the surface of the workpiece by an amount approximately equal to the height of the tooth.

When working in the middle zone saw teeth protrude above the surface of the workpiece by an amount equal to approximately one third of the radius of the saw.

When working in the central zone The center of the saw is located at the middle of the cutting height. This type of sawing is used in milling and sawing machines.

The peripheral and middle working zones of the saw are located on the upper or lower sections of the saw, which is observed in circular saws with a lower and upper saw shaft.

At divorce (Fig. 2, A) the tips of the teeth with a length of 0.3...0.5 of the tooth height are bent alternately in different directions. At flattening (Fig. 2, b) the tips of the teeth are flattened and shaped, giving them the shape of blades located symmetrically relative to the saw body.

The sawing rule can be formulated as follows: when inserting a tooth into wood, it is first extremely important to cut the fibers, and then, with the least resistance, separate them from the massif and remove the chips from the cut.

For longitudinal sawing (Fig. 5, A) the tooth with its main cutting edge cuts into the wood and cuts its fibers. The wedge of the tooth penetrates the wood and the front edge tends to press the cut chips away from the wood. Since the strength of the wood in the plane of the fibers is weak, the cut part of the chips breaks off and falls into the interdental cavity.

.°. The side cutting edges are not sharpened and left with a cutting angle of 90°. The saw tooth must have a cutting angle at the main cutting edge that is always less than 90

When cross cutting (Fig. 5, b) the work of cutting wood fibers is performed by the side cutting edges. For this purpose, the teeth are made with side sharpening. When teeth are inserted into wood to a depth of 0.8 mm, stresses at the bottom of the cut created by the beveled front edges of the teeth (Fig. 5, V), reach the limit of shear strength along the fibers and the cut fibers split either to the left or to the right along the fibers.

.° = 40...45j, and the side cutting edge is made with an oblique sharpening angle ° 90> dWhen cross-cutting wood, the main work is performed by the side cutting edges of the teeth, inclined forward and having beveled front edges. To ensure these conditions, the saw teeth are sharpened as follows: cutting angle at the main cutting edge

Saw tooth shape for longitudinal and transverse sawing - concept and types. Classification and features of the category “Saw tooth shape for longitudinal and cross cutting” 2017, 2018.

Wood is a valuable natural product created by nature and it is very important to learn how to use it correctly. After all, just as there is no identical fingerprint on a person, there is no similar tree in a forest. For many centuries now, humanity has been using wood for various needs: building houses, assembling furniture, skillfully creating decorative interior items and using it for industrial purposes. That's why correct processing cutting down a tree is a very important task facing the masters of their craft. As they say: “If you cut down a tree, then only to create a masterpiece!”

What is wood sawing? In a nutshell: it is the transformation of valuable natural resource into lumber, i.e. sawing - processing a tree trunk in any way to obtain material suitable for economic, technical and industrial needs.

To get out quality product, the raw materials for its manufacture must also be good. If trees of the required and correct sizes are used when sawing, then sawing a large amount of highly productive material from it will not be difficult. The main thing to remember are three fundamental factors: resource quality, shape and volume of wood And correctly selected types of wood sawing.

A good resource is a fresh resource. It is best to start working with wood immediately after the tree has been cut down. The more knotty and curved the trunk, the harder it is to obtain good lumber from it; therefore, before starting sawing, you need to sort the logs according to their quality characteristics, and only then use equipment for sawing wood.

There are no perfectly round trunks, so it is believed that a log has 4 sides, each of them consists of a quarter of a circle and occupies its full length. These 4 faces do not overlap one another. There is such a thing as a “clean edge”; the higher it is, the greater the value of the wood. This edge is free from various defects: cracks, scars, branches, chips, rot and damage.

Wood sawing technology

On an industrial scale, complex and expensive equipment is used to process trunks, and sawing wood at home takes place with a minimal set of tools: a hand and electric saw, a jigsaw. In order for the products to look neat, you need to know some features of the process.

You can start with sharpening the saw and bending its teeth. Sharpen it with a file. The teeth are set in different directions so that the saw blade does not jam in the cut. To do this, use pliers, and bend the teeth alternately, then in one direction, then in the other.
Before starting any woodwork you need make markings. To do this, rulers, tape measures, squares and other devices are used, and the line is drawn with a pencil, felt-tip pen, pen or marker. When marking the workpiece, it is necessary to ensure that areas with defects do not fall into the sawing zone.
Sawing wood with your own hands involves fixing the workpiece any of the mounting methods. This can be a clamp or a miter box, when the workpiece is sawed at a certain angle.
The next stage is Sawing It is best to start cutting the workpiece in the longitudinal direction, and only then in the transverse direction. All movements when working with a hand saw are made in jerks and swings. If the saw is electric, the process will happen faster. For sawing at home, you can use a jigsaw; it is usually used for hardwood or large workpieces to facilitate the worker’s efforts.

Modern woodworking machines allow you to speed up the processing process both at home and in small and medium-sized businesses. A band sawmill is one of the mechanized methods for preparing lumber. Sawing wood on a band sawmill occurs along the trunk, so any log can be used to make a beam, board, veneer or gun carriage. Such a machine can work with any type of wood: soft and hard, as well as highly resinous, producing edged and unedged boards. The entire process of work on such a sawmill consists of only 3 steps:

Preparatory stage, when the workpiece is given the required shape and also adjusted to one size.
Actually processing stage, when the operator configures the operating parameters and then presses “start”.
The final stage when a specialist manually corrects minor errors left after the machine’s operation.

Cutting tool for sawing wood in this case it is a 60 mm wide band saw. The principle of its operation is based on sawing a stationary object, fixed between two guides with fixed movable stops, with a horizontally moving saw blade. The thickness of the resulting material is set at your discretion. If different types of wood are processed at the sawmill, then you need to carefully monitor the settings for a specific material. It is necessary to ensure that the workpiece feed speed is set correctly so as not to break the saw. A system for regulating the supply of lubricating fluid is necessary to ensure that waste from sawing wood (sawdust) does not stick to the saw teeth and saw pulleys. This significantly extends the life of the equipment.

Laser cutting when sawing wood increasingly used for reasons of economy, increased productivity and increased processing accuracy. Thanks to precision cutting, this processing quantitatively reduces waste and minimizes leftovers. Laser sawing of wood also heats the cut, so the material can last longer due to the protective layer formed. This industrial processing of the barrel does not require any special effort to complete the operation; it is possible to cut material of almost any thickness. Due to the fact that wood is a flammable element, the laser cutting area must be cooled to prevent fire.
Wood sawing machine used only on an industrial scale. These are large bulky units with high labor productivity, allowing them to work continuously (in shifts) under heavy loads. These machines include:

Circular saw - it is designed for cross-cutting, longitudinal sawing, and angled sawing, with a circular saw as the cutting tool.
Multi saw machine - it is used for sawing and cutting wood materials; several saws are involved in the cutting process sequentially or simultaneously.

Wood sawing line– already a whole complex, which can consist of one or several machines. This is expensive equipment that can only be used if available large quantity raw materials. There are several representatives of this class of machines:

Splitter sawing line allows you to saw and split logs of any type of tree. The work is performed by a circular or chain saw. This line is distinguished by its ease of operation and maintenance, and is well suited for thin gauge and large logs.
Round timber processing line designed for processing timber into the output of edged round timber, sawdust and chips, timbering and processing of boards. They have two saw modules and a pneumatic system for removing sawdust.
Log sorting line designed for sorting logs in order to optimize sawmilling and obtain maximum yield, as well as cutting productivity and in monitoring the volume of purchased logs.
Optimization line automates the supply of timber at the input, replacing completely manual labor when feeding trunks.

If you decide to start your own wood sawing business, then first you should decide on the volume of lumber production, and then you will decide what method and equipment to choose for this.

Wood sawing services

How much does it cost to cut wood?– the question is rather rhetorical, it all depends on who will carry out the work and how it will be done.

Such services can be provided by organizations for the removal of unnecessary green spaces, immediately after the removal of the tree. If the plant was small or there are a number of defects in the trunk, then such wood is used in economic activities or the trunk and large branches are sawed for firewood. When more than one object is removed, for example, for planned construction, and the tree stands are of industrial attractiveness, then we can already talk about the value of such lumber.

In order to start cooperation with a company, sometimes it is necessary to conclude a contract for sawing wood, which will indicate all the technical issues, the timing of the work and the cost of this process. You can draw up an estimate - this is a document that indicates how the work will be carried out and in what way, and also indicates the type of wood, because different types of wood are also cut and processed differently.

There are a great many types and classifications of wood: hard, very hard, soft, seasoned, resinous, with and without knots, etc. It is clear that the harder it is, the more difficult it is to process, and the more knots it contains, the more waste there will be.

When cutting a log, the location of the fibers is also taken into account. Hence, three types of sawing are distinguished:

Radial sawing of wood(with a chainsaw or using longitudinal sawing machines) is a method of processing a trunk in which the fibers in the resulting board run along the direction of the growth rings. This type of sawing gives a larger amount of the resulting product at the output, and is superior in strength and hardness to all other types of wood processing. Such lumber is uniform in texture and color, and the inter-ring dimensions are minimal. The resulting radial cut boards are practically not subject to deformation, are more wear-resistant and have a lower percentage of shrinkage.
Longitudinal sawing of wood performed by machines or on a sawmill. With this processing of raw materials, veneer, carriage, edged and unshaped boards, thin gauge, and ordinary timber are obtained. Small trunks and thin logs are used.
Tangential sawing– this is the processing of material in which the cut plane passes at a distance from the core tangentially to the annual rings of the trunk. This product has a pronounced texture, and the pattern of annual rings is wavy. This type of sawing has a higher shrinkage coefficient, but the price is more affordable than radial sawing.

Home sawing and planing of wood– a manual method of processing wood. It is used to produce single copies of products and decorative items of artistic value.

Sawing frozen wood

This type of sawing is highlighted in separate category not by chance, since the processing of this type of raw material occurs quite often, but according to quality characteristics differs significantly from conventional dry and fresh raw materials. Logging areas are often developed in the cold season, so the flow of frozen wood to processing points practically never dries up.

Manufacturers of cutting tools produce saws specifically for working in winter conditions, and accordingly, the equipment used for sawing must be configured for frozen raw materials. The fact is that such wood sawing (price and terms are specified separately) has different physical and mechanical properties than usual. Freezing moisture affects the increase in the strength of frozen trunks, therefore the design of the cutting tool must correspond to the processing mode. There may be a decrease in machine productivity, but the resulting material is more durable, so improving processing mechanisms is the only solution assigned task.

"Arborist" offers a service such as sawing of wood with on-site visits to the customer. This is a very convenient way that allows you to solve your problems without even leaving your site. We can also buy and transport firewood, taking up space near your home. You make a profit and get rid of unnecessary wood. In addition, our specialists can carry out any work on removing unnecessary trees, as well as crowning and trimming dangerous elements using special equipment. All equipment that our specialists work with is certified and adjusted, and our employees are equipped with a license for their services. By contacting our company, you will first receive advice and answers to all questions.

Sawing wood video

Wood is a valuable natural material created by nature itself. People have been using this wonderful raw material for many centuries to build houses, create furniture, decorative interior items, and also use it for industrial purposes. For these reasons, proper processing of a felled trunk is an extremely important task. Sawing and planing wood are the most important operations with wood. In this article we will talk about what wood sawing is and what types of sawing exist.

Log sawing is the process of converting valuable natural raw materials into lumber. When sawing wood various methods lumber can be obtained in various sizes. To obtain high-quality products, you need to choose high-quality, even logs that are not damaged by pests.

Types of wood cutting

The quality of the final product depends on a large number of factors - the type of wood and the quality of the raw materials, the professionalism of the workers, and proper drying. However, there is another important aspect - this is the method of cutting timber.

There are the following cutting methods:

tangential
radial
rustic
longitudinal
transverse.

Rustic is a cut that is made at an acute angle to the direction of the grain. This method is used in the manufacture of lumber for rustic flooring, which can be called the most heterogeneous and original in pattern and shade.

During tangential cutting, the cutting plane lies tangentially to the annual layers of the material at a certain distance from the core. Since wood fibers are most often located in different directions, a natural pattern in the form of fancy “arches”, “curls”, “rings” is obtained on the surface. The structure of the board with this cutting option is heterogeneous; wood pores may be present. At the end of the tangential cut, the boards are characterized by an increased coefficient of shrinkage and swelling. Also, this log sawing scheme makes it possible to increase the useful yield coefficient, which causes a reduction in the cost of the final product.

Sawing wood blanks using the radial method is carried out perpendicular to the annual rings. Thus, a homogeneous board is obtained with the smallest gaps between annual layers. This creates an attractive pattern and also increases the strength of the lumber. Radial materials are characterized by high resistance to deformation and wear resistance. Also, such boards have more low performance shrinkage and swelling compared to tangential sawn timber. Therefore, finished products, for example, parquet boards, floorboards, block houses, linings, practically do not crack on the front part, but tangentially sawn materials are susceptible to such phenomena. Glued laminated timber is created only from radial and semi-radial cut boards, because the mechanical and geometric parameters are directly dependent on the resistance of the fibers. This resistance increases during gluing of layers with multidirectional annual rings at an inclination angle of no more than 45°.

Only 10-15% of radial boards can be obtained from a single log. Therefore they have a high cost. The best performance is demonstrated by material having an angle between the annual layers and the cutting plane from 80 to 90 degrees.

Sawing wood across the grain

The technology of sawing wood across the grain is the most common method of processing timber in carpentry. At the same time, such sawing can be called the simplest. Longitudinal sawing wood requires much more effort and certain skills.

Tools for cross-cutting timber are selected depending on the required accuracy, the amount of work and the conditions available in each individual workshop. You can use:

electric circular saw. She makes neat and fast cuts. For domestic use, a model with a 1000 W motor and a disk cross-section of 180 mm is perfect. Most circular saws come with a combination blade, which can be used to implement the most various works. The teeth of this blade are something between the teeth of a transverse and longitudinal saw. For long work It is better to take a blade that is coated with carbide. Its cost is higher, but it takes 10 times longer to dull
miter box and tenon saw. They are used for finishing. These tools can be used to make the most precise cuts.
circular saw
cross saw. When purchasing, please note that the teeth of such a tool should be alternately positioned to the left and to the right of the blade itself. They must be well sharpened and beveled. The most popular is a saw with 10 teeth per 25 mm blade. With 8 teeth, the saw will cut faster, but will create rough cuts.