How to properly install the blade on a hacksaw

Types of hacksaw blades

GOST R 53411-2009 “Hacksaw blades for metal” establishes two types of such tools. for machine and manual cutting. We will not touch on the first ones, but the second ones are produced in three main standard sizes:

• Single, with a distance between the fixing holes 250 ± 2 mm, with a total blade length of no more than 265 mm;
• Single, with a distance between the fixing holes of 300 ± 2 mm, with a total blade length of no more than 315 mm;
• Double, with a distance between the fixing holes of 300 ± 2 mm, with a total blade length not exceeding 315 mm.

In this case, the thickness of the leaf s of a single version is 0.63 mm, of a double one. 0.80 mm. Height with a single row of tines is 12.5 mm, and with a double row is 20 mm.

GOST also regulates the values ​​of the pitch of the teeth P, mm and their number z, which for the first type of blades are 0.80 / 32, 1.00 / 24 and 1.25 / 20, respectively. Owners of longer hacksaws, in addition to those listed above, can also use hacksaw blades with parameters 1.40 / 18 and 1.60 / 16.

According to the brand of material used for the manufacture of hacksaw blades for metal, they are made from tool steels:

• H6VF brands.
• В2Ф brands.
• High speed, grades P6M5, P12 or P18.

The assortment of domestic hacksaw blades is exhausted by this, however, so-called diamond blades with surface spraying with titanium nitrides or other refractory metals are widespread in specialized retail chains. These canvases can be easily distinguished by their color: ordinary steel canvases are dark gray, and the sprayed ones can have different colors. from bright orange to blue (depending on the manufacturer).

High strength of hacksaw blades for metal is ensured by appropriate heat treatment. On the surface of the blade, two zones with different values ​​of hardness are distinguished: directly at the teeth it ranges from HRC 64. 67 for alloyed tool steels to HRC 73. 78. for high-speed steels (for diamond blades this parameter reaches HRA 82. 84), and in the rest zone. НRС 44. 46. A significant difference in hardness confirms the high sensitivity of the product to bending stresses, therefore, the standard also limits the maximum force applied to the hand hacksaw. It should not exceed 60 kg when working with blades with a tooth pitch of less than 1.4 mm, and 10 kg for blades with a tooth pitch of more than 1.4 mm.

How to install a blade on a hacksaw for metal?

The installation method is determined by the design of the fastening system on the hacksaw itself. In the case of a threaded clamp, the file is slid onto the corresponding projection, tightened slightly, and then secured with a wing nut. With sudden changes in the load on the hacksaw, such a mount will have to be checked periodically. For hacksaws with a lever-type device, the installation and replacement process is simplified: just pull out the lever located on the side opposite to the handle of the hand-held hacksaw, put on the blade, and return the lever to its original position.

When tightened correctly, the blade should make a slight ringing and vibrate slightly. During operation, such a canvas should not change the direction of its movement under load.

For single sided blades, it is important to correctly position the direction of the tines. Their slope should be directed away from the handle. Most workers make the main working movement away from themselves, when the metal is cut. The reverse movement is only intended to return the hacksaw to its original position. When trying to cut metal and during idling, the geometry of the teeth, which is not adapted to such loads, will tear the tooth from the base, and as a result, the blade may collapse. This phenomenon is especially true for diamond blades.

Recently, the so-called bimetallic blades (designation. BIM) have become popular, when a high-speed steel strip is welded onto the main strip of hardened structural steel such as steel 45. Here everything is decided by quality: for Chinese-made saws, the metal grade is most often not guaranteed (as, indeed, the quality of welding), therefore, when working with durable metal, there are often cases of delamination of bimetallic blades.

The blade is inserted into the hacksaws for metal with the tooth forward (and, of course, down), so that the working movement during which the sawing is carried out is “forward”.

The holes in the canvas are either put on special projections on the frame of the hacksaw, or (as done in Soviet models. I like this method more, it has higher rigidity) inserted into the slot, in which it is fixed with cotter pins, they have long been lost in my hacksaw. I use trimmings nails.

after that, the blade is tightened with a screw. Personally, I usually twist the screw (“how much it turns”. all the way. It never came out to break the canvas, and it’s not convenient to work with a weak tension. the file “walks”)

In order to remember once and for all how to correctly insert the blade into a hacksaw for metal, you need to understand the principle of the blade itself and its cutting method.

So the canvas scrapes metal with its teeth, each small tooth scrapes a little, a little metal, and since there are several dozen of them, with each wire of the canvas there is a tangible depression, which is called a cut.

So the blade for metal has the direction of the teeth in one direction, this is done in order to make it easier for the teeth to scrape the metal.

Due to such features, the blade is installed exclusively with its teeth away from oneself, since during cutting, the worker’s effort is applied when the hacksaw is directed away from himself, and when it returns, the force is removed.

That is, the principle of a file, so the teeth are set away from you, from the handle of the hacksaw.

Now, regarding the tension, the canvas should be stretched very tightly, but you need to tighten the adjusting lamb by hand, if you use a lever or a key, but you can simply break the canvas, and of course you need to make sure that the canvas itself is perfectly level, without scrolls and bends, if suddenly The hacksaw is already experienced and the blade becomes uneven in it, you need to either eliminate this defect, or achieve the maximum even blade in the hacksaw. otherwise, you will just break out the teeth, and the blade will warm up and get stuck in the cut!

A hacksaw for metal is a hand tool that is used to cut profile metal and pipes. The simplest hacksaw for metal consists of a machine and a hacksaw blade. The machine, in turn, consists of a frame, into which on one side a handle is inserted with a device for fixing the web, and on the other hand, a device for fixing and adjusting the tension of the web. The tensioning device, on the one hand, has a groove for inserting and fixing the web, and on the other hand, a screw with a ram with which the web is tensioned.

Hacksaw blades for metal differ from each other in width, length, thickness, distance between teeth and their height. The use of a particular blade depends on the thickness, hardness and shape of the material to be cut. The fabric makers have made sure that you can choose the right fabric for the material you need to cut, be it aluminum, copper, bronze or even plastic. The blade dimensions, namely length, width, tooth dimensions and steel grade, can be found on the purchased hacksaw blade.

How to install a blade in a hacksaw for metal?

As shown in the first picture of the article: teeth down (if the blade is one-sided) and the teeth are directed forward, away from the handle. When you are sawing, you are applying downward and forward pressure. in the same way the teeth of the hacksaw should be directed, downward and forward. To install, loosen the tension screw, remove the old blade from the pins, put on a new one and tighten so that the blade sounds like a string from the click of your fingernail. The main thing here is not to overdo it and not to tear the canvas. Experimentally, you will find the optimal tension.

The tension is made with the help of the ram on the adjusting device, that is, by twisting the ram you will stretch the canvas. So when pulling the hacksaw blade, you need to find a middle ground. Also, make sure that the blade is installed evenly, without distortions, since the distortion will lead to an uneven cut during cutting.

Principles for choosing a canvas

The selection criteria are:

• A type of manual hacksaw for metal, more precisely, the distance between the mounting holes. It is better if it is variable, then a hacksaw blade of any standard size is suitable for work.
• Tensile strength of the cut metal. If the tool is supposed to be used to separate soft, ductile metals. copper, aluminum, etc., then it is advisable to have a hacksaw blade with the lowest hardness. H6VF steel can be adopted as a material; imported canvases have the designation HCS on the lateral plane. High-speed steel blades are suitable for cutting harder metals (corresponding import marking. HSS).
• The thickness of the metal to be cut and the quality of the separation surface. Foreign practice recommends using the PPI parameter as a selection criterion. the number of tooth vertices per inch of blade length. So, for thin metals, where a very smooth cut surface is required, the PPI24 value is considered correct. If for the user the main factor of productivity than quality, then PPI should be

The quality of the coating also affects the durability of the hacksaw blade. For domestic tools, the most common coating is Khim.Oks.Prm, less often tools with nitroenamel coatings such as NTs-25 or NTs-132 are found. It should be remembered that under prolonged loads, when the file heats up, the enamel can crack.

When choosing a high-quality hacksaw blade, you should pay attention to the uniformity of the tooth setting: in high-quality products, this parameter should not exceed 45% of the tooth pitch over a length of 10 mm. Product quality can also be assessed by the parameter of equal height of the teeth: the difference in adjacent vertices should not exceed 0.10. 0.15 mm, which is checked using a micrometer or a depth gauge.

How to cut?

Since you were interested in the question of installing the blade, then advice on how to use a hacksaw for metal will not hurt. Grasp with one hand (right if you are right-handed or left if you are left-handed) by the handle of the hacksaw, with the other. by the vertical edge of the hacksaw arc opposite to the handle. Place the blade on the line to be cut. Aim the blade strictly in the direction of the cut line. Keep the angle of inclination of the hacksaw small. The web should almost rest on the part, usually at an angle of 30-45 degrees. This will result in less vibration, less noise and a smoother cut line. Cutting across the material, with an angle of 90 degrees, is only worthwhile in emergencies, for example, when turning the mowing line of the cut. The smoother the cut line you need, the smaller the angle of inclination.

The first movements should be done with little effort so that the blade cuts into the material and does not slip away from the cutting line. Making smooth movements, strictly forward, press the hacksaw against the part when moving forward and release the pressure when returning to its original state. When the canvas clings to the material, you can work with all your might.

The range of motion is maximum, from the edge of the blade to the edge, without hitting the part with the arc of the hacksaw. There is no need to “mark time”. this way you will quickly erase the canvas in one area and have to throw it away, because it is impossible to use the damaged canvas. Keep the arc of the hacksaw straight, do not let it bow in different directions. The direction of cutting corresponds to the plane of the hacksaw arc, so bumping is contraindicated here. In addition, the blade breaks easily with sharp jerks of the hacksaw to the side. The material properties of the web are such that it holds the longitudinal tensile force very well, but is very fragile in bending.

Hacksaw for metal how to put the blade correctly

The blade for a hacksaw for metal is one of the most short-lived elements from the entire range of consumables for tools. Of course, a lot depends on the technology of working with metal and the skills of using a hacksaw, but first of all you need to be able to make the right choice of the blade. Today, we will talk about the choice and types, and also learn how to easily change the hacksaw blade.

Cutting with a hacksaw on a curved mowing line

A hacksaw for metal is also valuable because it allows you to cut along almost any curve of the mowing line. In order to cut in an arc without stopping the forward movement of the hacksaw, align it perpendicular to the end of the material of the part (i.e., the angle of inclination is 90 degrees) and gradually smoothly turn the arc of the hacksaw so that the blade follows the intended mowing line. Yes, it is always necessary to mark the line of the cut with anything. with a pencil, marker, scratch with a nail. The main thing is to be seen when you work. The rotation of the canvas must be done as gently and smoothly as possible, otherwise it will break; turns are extreme for a hacksaw blade for metal.

If you need to make a sharp turn, say, 90 degrees, you will have to practically “mark time”, continuing to saw and smoothly turn the arc of the hacksaw, periodically stepping back so as not to go far from the turn, using the other side of the material to turn the blade which is external to the part.

To cut the inner corner, you first need to drill a straight line with a thin drill slightly longer than the width of the blade, thread the blade into this groove and cut further with a hacksaw. In general, practice will show how this is done. Nothing complicated here.

The picture below shows another way to use a hacksaw for metal. For this method, you need to reinstall the canvas by rotating it 90 degrees.

Hacksaw blades for metal

Choosing a hacksaw for metal

When buying a hacksaw, pay attention to the frame of the tool, since the blade can be replaced at any convenient time, but the frame cannot. A high-quality frame is made of sufficiently durable composite materials, or metal. A useful feature is the ability to change the angle of inclination for the hacksaw blade, which allows you to work even in the most inaccessible places

A useful function is the ability to change the angle of inclination for the hacksaw blade, which allows you to work even in the most difficult to access places.

It is also necessary to pay attention to the tool handle. After all, it is for this part that you will hold the hacksaw, so it, in turn, should be very comfortable, sit well in your hand, and, if possible, have special finger rests. The handle of the tool must be solid, and not have hollow parts, since in this case it may simply break

In general, it should also be noted that the hacksaw must be tightly assembled, not have any backlash or other defects. this will guarantee its high quality.

The handle of the tool should be solid, and not have hollow parts, as in this case it may simply break. In general, it should also be noted that the hacksaw must be firmly assembled, not have any backlash or other defects. this will guarantee its high quality.

Choosing a blade for a hacksaw for metal

When choosing a hacksaw, you also need to pay attention to the tool blade. It should not have any cracks or traces of corrosion, it should be as clean and smooth as possible. To check the canvas, it is enough to bend and release it, after which it should instantly return to its original state

To check the canvas, it is enough to bend and release it, after which it should instantly return to its original state.

Also note that metal hacksaw blades can have 18, 24 and 32 teeth per inch. The higher the number of teeth per inch, the faster and more comfortable it will be to saw metal.

And, of course, if the hacksaw has the ability to set the blade at an angle of 90 °, this suggests that such a model of the tool is worth paying attention to.

articles from the section:

Mowing line curved cut

Compact and full-size hacksaws can cut any type of mowing line. If it is necessary to produce round cuts, the saw is aligned so that it makes a right angle with the part. Turn the bow slowly so that the tool follows the selected line. Marking can be done with a marker or sharp object. It is impossible to make sharp turns, this contributes to a deterioration in cut quality and tool breakage.

How to install a blade on a hacksaw for metal

The installation method is determined by the design of the fastening system on the hacksaw itself. In the case of a threaded clamp, the file is slid onto the corresponding projection, tightened slightly, and then secured with a wing nut. With sudden changes in the load on the hacksaw, such a mount will have to be checked periodically. For hacksaws with a lever-type device, the installation and replacement process is simplified: just pull out the lever located on the side opposite to the handle of the hand-held hacksaw, put on the blade, and return the lever to its original position.

When tightened correctly, the blade should make a slight ringing and vibrate slightly. During operation, such a canvas should not change the direction of its movement under load.

For single sided blades, it is important to correctly position the direction of the tines. Their slope should be directed away from the handle

Most workers make the main working movement away from themselves, when the metal is cut. The reverse movement is only intended to return the hacksaw to its original position. When trying to cut metal and during idling, the geometry of the teeth, which is not adapted to such loads, will tear the tooth from the base, and as a result, the blade may collapse. This phenomenon is especially true for diamond blades.

Recently, the so-called bimetallic blades (designation. BIM) have become popular, when a high-speed steel strip is welded onto the main strip of hardened structural steel such as steel 45. Here everything is decided by quality: for Chinese-made saws, the metal grade is most often not guaranteed (as, indeed, the quality of welding), therefore, when working with durable metal, there are often cases of delamination of bimetallic blades.

Choosing a band saw blade

To get the right tool, you need to test it against a number of parameters. This prudence will allow you to achieve an even cut mowing line, the absence of cracks and chips on the workpiece. For cutting tools, several types of blades are produced, which are designed to work:

• with a stone;
• metal;
• tree;
• synthetic materials.

How to choose a tool and canvas

When choosing a saw, you should pay attention to the distance between the fasteners. It is necessary to purchase a tool into which replacement parts of various sizes can be inserted

When buying a hacksaw blade for metal, the following parameters are taken into account:

• The strength of the processed material. If the saw will be used for cutting soft sheets, use a blade with a minimum hardness, made of steel grade X6VF. A professional hacksaw is equipped with parts made of high-speed materials. High cutting quality is ensured by diamond or tungsten blades.
• The thickness of the processed sheet and the quality of the cuts. The selection criterion is the number of teeth per inch of material (PPI). For cutting thin sheet metal where smooth edges are required, it is recommended to select parts with a PPI greater than 24. If cutting speed is more important than quality, the index should be less than 24. The PPI increases as the tooth frequency increases.
• Coating type. Russian-made tools are coated with Chem.Oks.Prm. Less commonly, you can find files with an enamel coating. It must be remembered that with prolonged use, the enamel may crack. There are bimetallic products when a high-speed metal strip is applied to a steel strip.
• Uniform direction of the teeth. The points should not deviate from the axis by more than 45% of the pitch of the teeth.

Hacksaw blade for metal

Circumferential

The circular saw is considered a specialized tool, due to the small width of the blade, it allows you to cut curved parts. The main task of such a device is reduced to the possibility of cutting sheet material when it is necessary to work along clearly defined contours.

A narrow web is considered more maneuverable.

Circular saws are quite light and compact, often the cutters are located on both sides and may differ in size. Thus, it is possible to cut with different degrees of purity. If you buy a model with fine teeth, then the cut will turn out to be smooth and even.