What kind of saws are used for making crosscut or lengthwise cuts?. Rules for felling wood
Sawing wood crosswise or lengthwise. Saws for wood
For Sawing wood crosswise or lengthwise many saws are used. Saws blades are made of rolled tool steel.
The teeth can be set in a straight line or in a bow shape (arbor saw). Depending on inclination of their front faces we make saw blades with front teeth. sharp-angled; with straight teeth. rectangular; with back teeth. blunt-angled wood sawing saws with teeth with backward angulation are used across the grain, and saws with teeth with forward angulation (straight) are used lengthways across the grain. Distance t. tooth pitch, h. their height.
To avoid sawing the blade gets stuck in the wood the teeth are alternately bent on both sides. set. Sawing heads for soft, damp wood are increasingly set in a slightly wider area than the saw blade. A saw with a larger setting requires more effort and produces a larger kerf.
When sawing the board, lay it right side up and mark the place of the cut with a ridge. Then the board is positioned so that the shorter part of it can hang down freely from the uprights. When sawing off the next part of the board, place it on the support. The saw is at a slight slope to the horizontal plane
if the angle is too steep, the wood fibers will bite out of the saw from below and the cut will not be clean. After the saw has sunk into the wood where the cut is marked the sawing operation is continued so that the cut trimmer line is perpendicular to the area of the board to be sawn. Do not apply too much pressure on the saw. When finishing your work it is necessary to hold the saw loosely, slowing down and at the same time holding the sawed board partially with your hand to prevent the lower fibers from splitting.
At When sawing off wood the saw has to be clamped along the fiber so that it is stationary. When sawing long boards, it is necessary to secure them with ties so that the sawn-off part of the board hangs over the edge of the table. If the saw blade is not straight, it is not possible to keep it on the cut line. When sawing, do not swing the saw up and down and keep it tilted to get a clean cut.
There are three basic ways of sawing wood: end to end, lengthwise and crosswise. Wood is sawn with saws which are steel blades, bands, or after marking, the wood can be sawn, chopped, drilled, and planed.
When wood is sawed transversely, the main cutting edge of the tooth cuts across the fibers., a Cross-cutting saws cut wood fibers by lateral edges, and.
A distinction is made between sawing across the fiber. cross sawing and along the fiber. longitudinal sawing. Cross-cutting sawing. Large pieces of wood are cross-cut in a coarse cross-cutting manner using an ordinary cross-cutting saw, the teeth of which are “sharpened” in the front and back.
Sawing raw wood, roughing and coarse cutting of large boards and squared timber of softwood is done with the coarse-toothed saws. Because of the heterogeneous structure of wood, it is necessary to use saws with.
A chisel is a carpentry or carpenter’s tool designed for chiseling out grooves, nests, and other work. This tool has an elongated metal bar with a sharpened working tip that is supported in the handle. The chisel has a crimping ring at the end of its handle that protects it from possible splintering by blows of the hammer. Carpenter chisels have a tapered tube instead of a shank, into which the handle is inserted, and a solid blade that tapers slightly towards the sharp end. Carpentry chisels are thicker than carpenter chisels.
A jointer is a carpentry or carpenter’s chisel designed for work with thin materials, such as fitting and trimming joints, rebating grooves and slots, chamfering, etc.д. A chisel consists of a sharp blade and a handle. Depending on the sharpening of the working part and its shape, chisels are either flat or semicircular.
Saws for wood
Option #1. narrow
Small narrow saw is a design that consists of a straight, flat blade and a handle. It is used for thin work: cuts through, sawing curved pieces.
This type of tool is designed for sawing wooden pieces with thickness not exceeding 8-10 cm, for cutting small branches and minor work in the garden
When making narrow models, manufacturers install blades with triangular bilateral teeth, or with parallel sharpening. The disadvantage of the tool is that the blade can deviate from the specified direction when pressed in the process of work.
Variant #2. Regular
The standard handsaw can be equipped with any type of teeth and often comes with interchangeable blades of different types and designs.
To be able to saw off workpieces at a certain angle with a standard hand saw, special jigsaws have to be purchased
But despite the claimed versatility of their application, it is not desirable to use saws of this type in furniture making.
Option #3. with a shank
Both narrow and conventional saws tend to bend as the stiffness of the material being worked increases. In these cases, it is effective to use blades with a shank that acts as a kind of rib.
Handheld hacksaws, equipped with a shank, are designed to create shallow cuts in any thickness of wooden surface
The presence of the shoe does not allow the saw to make a cut deeper than the width of the blade, as it prevents the cutting blade from penetrating further into the wood.
Variant #4. beam type
Ray type saws are more bulky devices, acting as an analogue of an electric jigsaw.
The main purpose of this type of saws is to create a precise cut when working with surfaces located at any angle
Thanks to its solid construction and screwed connections of handles, beam type saws can easily overcome knots, making cuts in radiuses and curvilinear contours.
Depending on the purpose and design, the saws can be:
- Swing-type. for longitudinal cutting;
- transversal. for sawing workpieces across the wood fiber;
- cupped. for hole cutting, rounding and shape sawing;
- tenoned. for cutting of connecting tenons, as well as for sawing of simple geometrical figures on the workpiece.
Only with a bow-type hacksaw you can cut the material lengthwise and crosswise, sawing blanks with complex lines and doing the work alone without an assistant.
How to make the right choice when buying, characteristics
If you are tired of suffering every year with a hand saw when pruning trees in the garden, and you decide to buy a sabre saw for such work, you can choose the cheapest and simplest model. you will not be mistaken. If the saw is purchased for a wider application, it is necessary to study the characteristics of the most common models.
The first thing to pay attention to. the power of the tool.
By choosing a stronger motor, the customer chooses a higher output. However, it should be taken into account that together with the power the weight, size and price of the machine increase. Vibration is more noticeable on heavy-duty models with a long blade and this makes it necessary to install an anti-vibration system, the price of which adds to the cost of the tool.
crosscut sled for a table saw [plastic runners that will last forever!]
The 300-550 watt setting will be sufficient for home use.
Most professional machines have a power consumption of 900-1200 W. Such power makes it possible to work with larger objects, increases kerf depth in hard materials.
As you know, different speeds are used for processing different materials. Saw blades have a stroke frequency of 300 to 3,500 strokes. Changing the value by varying the amount of pressure on the starter button. Some models are equipped with a continuously variable setting.
This feature makes the sabre saw faster, reducing saw blade heat. On advanced machines the pendulum stroke is made adjustable.
Function of the saw shoe
This detail allows you to set the tool against the workpiece, which provides convenience to the operator, increasing the speed and quality of sawing.
Moving the stop changes the outreach of the blade, on some models it can be rotated, tilted to fit a difficult part, to make a bottom-up cut.
The maximum cutting depths depending on the material can be found in the data sheets. The Skil 4900AA reciprocating saw has a cutting depth of 30 mm in metal for example.
Wood hacksaw. choose your tooth size
Even if you already have a hacksaw in the household, it is quite possible that it will not be suitable for your purposes, so sooner or later you may need to go for a new saw. When choosing this tool you will need knowledge about its structure and features. If your saw has straight teeth it is easier to cut wood crosswise than if you cut wood lengthways you will need a saw with angled teeth. According to their inclination the hacksaw will be transverse or longitudinal. If you are a frequent craftsman, you will need both.
Sawing is fastest with a hacksaw with big teeth, but you will not get a smooth cut edge. For garden work or a quick cut through rough boards, this is the right saw for you. For a cleaner edge of the cut use a tool with a fine tooth, but it is slower to work with such a hacksaw. it is more difficult to remove sawdust from the cut.
With a very fine tooth joiner’s hacksaw is used by carpenters-professionals, in the household it is hardly useful. There is also a mechanical hacksaw. it is a small machine with a mechanically movable blade, such are used in factories for sawing metal pipes and other elements made of metal, in the home workshop it will be replaced by a hacksaw for metal.
Combining these factors, manufacturers have developed and now produce standard products with different blades, handle and tooth shapes. To understand how to choose a wood hacksaw, we first need to get acquainted with the existing types of saws.
Type 1: Classic
A basic type of saw, which almost every man has, even far from construction and carpentry. This hacksaw can be fitted with blades of any length and number of teeth, and is often equipped with interchangeable blades, which are included with the purchase.
Type 2: Narrow
Another name for it is the circular saw. Takes its name from its main application. it is used to cut out lines in different shapes, and does it accurately and precisely. Also used for sawing through round, square holes. Saw blade is narrow, the teeth are frequent, and can be on one or both working planes.
When working with the saw, you should be careful: with an uncertain movement the blade will turn in the other direction, so the choice of a wood hacksaw with a narrow blade should stop at the product of quality hard steel, which will not bend in the process of sawing.
Type 3: With over
Hacksaw with scoring block is equipped with reinforcing ribs (the same block) that prevent the blade from bending during cutting. Thus, the tool is not able to make a cut lower than the width of the working part of the saw.
The tile cutter always has a comfortable handle at a 45 0 angle to the blade for easy performance.
Type 4: Beam
The onion saw is indispensable for metalwork: it is used for cutting rough parts of trunks, knots, for sawing figures out of plywood and other wood materials, for sawing wood along and across the fibers. The archery saw is so widely used that it can replace a small woodworking machine on its own.
The large range of work to be done slightly obscures the main disadvantages:
- Bulky. The beam saw is a complex design, its supporting part is made in the form of a large curved arc, to which is attached narrow as a thread blade with teeth.
- Brittleness. Work with the tool must be very carefully: in the process of work the blade can fly off the mounts and tear, requires frequent replacement.
Type 5: Reward tool
The bowie saw requires a great deal of effort to learn how to work with it. It is a tool that resembles a planer. It is equipped with two handles. Its main application. cutting grooves and nicks, depth of holes and grooves can be different sizes, and, moreover, on the rocks of any hardness.
Type 6: Folding tools
A mechanical hacksaw that can be taken on camping trips or vacations. It is compact, lightweight and completely safe when folded. A folding hacksaw has fine teeth and a short, pointed blade.
Sawing wood by hand is done with saws of different designs, sizes and shapes.
Bow saws and hacksaws are mainly used in carpentry
The core piece of each band saw is a thin band of steel with one longitudinal edge along which some tooth geometry is carved. These teeth are bent alternately in different directions and then ground. The width of the cut is slightly greater than the thickness of the blade during cutting and the saw moves freely.
According to the teeth size joiner saws are subdivided into fine toothed (height of teeth up to 3 mm), normal or medium (height of teeth 4-5 mm) and coarse-toothed (height of teeth 6-8 mm). Small-toothed saws are used for fine, precise work (e.g., for sawing lugs and studs) and for cutting dry and dense wood. Sawing raw wood and roughing and coarse sawing of large boards and planks made of soft wood is done with coarse-toothed saws. Saws with different tooth shapes are needed for cross-cutting and lengthwise sawing due to the uneven structure of wood.
Cross-cutting saws with teeth in the shape of isosceles triangles sharpened on both sides are used for cross-cutting boards, cants and slats. These saws cut equally well in both directions of rotation, toward and away from the grain.
Saws with teeth shaped as oblique or, less frequently, rectangular triangles are used for sawing wood along grain. Longitudinal saws cut wood in one direction only. away from the person working. The teeth of this saw only slide along the base of the kerf when moving toward you.
When sawing boards, bars, planks and slats, the materials must be fixed so that they are not moving during the work. Figure 7 shows how to attach a board to a workbench and workbench for longitudinal sawing, and how to use blocking devices and sawing boxes for cross-cutting sawing.
Portable Circular Saw CrossCut Sled: Woodworking Jig
When sawing material it is recommended to place it so that the saw blade moves in vertical plane and trimmer line of the cut runs along the right edge of the marking line. Light must be directed at the material so that the markings are clearly visible to the sawing operator.
The working posture while sawing must be free and stable. To do this the person working on the saw holds his left foot forward and places the foot of the right foot at an approximate 70° angle to the left foot.
Before sawing, the saw blade is positioned on the edge of the board or bar, along with the marked line on the surface of the material (fig. 7,a, b). Hold the material with the left hand and the fingernail of the right thumb should touch the saw blade and guide the saw blade in the right direction when sawing. Carefully, without pressing the saw to the material, the saw is pulled toward you and, after the saw blade for the trimmer has been correctly outlined, begin sawing.
When sawing transversely the saw has to be moved freely to both sides with slight pressure. When sawing longitudinally the reverse movement (pulling the saw toward you) is done without any pressure at all.
Sawing plywood, in order to avoid so-called splintering, should be done with fine-toothed saws. For the same purpose the saw blade should be at an acute angle to the plane of the plywood sheet. Complex shapes and patterns in plywood are sawn out with a hand or power jigsaw.
Bow saws and hacksaws need to be sharpened and unwound systematically. This work is difficult for young technicians and is usually only done by a supervisor. Small triangular files are used for the saw point. The saw-blade is clamped between two wooden slats in a vice so that the teeth protrude upwards.
Other books in the Books for Teachers section: “With Your Own Hands.” “History of Science and Technology”
Sawing logs longitudinally
A log is a tree trunk, from which all branches, limbs, and the upper thin part of the crown are removed. A log can be used as an independent building material (poles, piles, masts), as well as a raw material for the production of lumber.
Sawing a log can be accomplished in several ways:
- Manually, with a sawing tool
- with the help of a sawmill
- Using woodworking machines or specialist lines.
For more rational use of available raw materials and proper sawing of logs the woodworking industry applies special sawing schemes which allow to reduce the percentage of waste and, consequently, reduce the cost of the final product. For this reason, before starting the process of sawing logs with their own hands, it is worth looking for similar schemes on the Internet and study them in detail.
For sawing logs, such longitudinal sawing machines can be used:
- A chainsaw and a simple hand saw help produce a small amount of lumber
- Sawmill is a device that can saw logs and cants, for which the saw is equipped with frame saws. Workpieces of a diameter between 14 and 80 cm and a length of 3 to 7 meters can be sawn on these devices
- circular saws. In such a device, the wood is sawn with a circular saw. Machines with one saw are called single-saw machines, machines with two saws. multi-blade saws. Single-blade circular saws are used in small workshops and bodyshops. Multi-sawing machines are used at large enterprises for cutting a large volume of blanks. Manual feed of the workpiece is forbidden on these machines. Circular sawmills have the inherent danger of ejection of material being sawn through and saw blades cutting in the opposite direction to the feed. That is why the control is kept clear of the material throw out of these machines. Circular saws also have wedge knives and special mechanisms that are designed to keep the material from ejecting
- Band saws are used for cutting logs with the band saw blade mounted on pulleys. They are designed to make longitudinal and compound cuts in wood and all types of wood-based materials. Such machines are used in joiner’s workshops, machine shops and are characterized by the big reach of the frame, big height of cut at small dimensions
- Log sawing lines allow for high surface quality of the final product, precise lines as well as high productivity. They are used in large factories.
In order to obtain a quality product it is necessary to use good raw materials. If the right dimensions and dimensions of timber are used for sawing, it is possible to produce high-quality materials.
The best materials are obtained from freshly cut wood. It is very difficult to get good sawn timber from a knotty and bent trunk. That’s why before sawing it is necessary to sort logs according to their quality features, and only after that use the equipment for sawing timber.
There are no completely round logs, for this reason it is considered that a log has 4 faces, each of which is a quarter circle and spans its entire length. Neither edge meets the other. There is a concept of “clean edge”, the higher it is, the more valuable the timber. This face has no imperfections such as cracks, scars, knots, splits, and rot.
Russian sawmills most often use sawmills for longitudinal sawing of logs. Nevertheless there is a worldwide trend towards the use of double and quadruple block band saw machines which are characterized by high productivity.
Board yield of sawn logs
|Diameter, cm||Yield of top grades, %|
|12. 16||40% first grade yield|
|18. 22||50% on average|
|24. 26||around 50 %|
|28. 40||timber, a rate of approx. 70 % in timber production|
|42. 60||about 60. 70%|
Cross-cutting sawing technology is the most common method of timber processing in the joinery industry. This is also the easiest sawing to do. Longitudinal sawing requires considerably more effort and skill.
Tools for cross-cutting timber are chosen according to the precision required, the amount of work and the conditions in each individual workshop. You can use: