Hacksaw For Metal How To Put The Blade Correctly

20th November 2020

Sawing process

Metal cutting with a hacksaw is carried out as follows:

With one hand they hold the handle, with the other. the vertical part of the arc;
The blade is aligned according to the cut line of the cut (the saw should be tilted at an acute angle and move, almost adhering to the sheet, which will help to avoid unnecessary noise);
The first movements are done with little effort; this will help the teeth cut into the metal and prevent the tool from slipping;
With smooth progressive movements, the file is moved forward (when the blade returns to its previous position, the pressing force is reduced);
After the appearance of the slot, they begin to work at full strength.

The range of motion should be large. You can not touch the part with the arc of a hacksaw and linger in place for a long time. This will damage the tool, which will require purchasing a new replacement part. The hacksaw must be held in one position, not allowing it to deviate to the sides. With sharp movements of the tool, the file becomes unusable.

How to properly saw with a hacksaw for metal

The general theory of sawing with a hacksaw for metal looks like this:

Looking at this picture, you can suddenly become sad, so the further presentation of the material will be based on solving those problems that have arisen in the course of the recent accidental practical application (in economic theory, this is called learning-by-doing) of this ancient tool and the corresponding technology for cutting metals.

So, let’s start with the fact that you need to cut with a hacksaw for metal horizontally, grabbing the tool with both hands. Why would it be good to use a hacksaw with a well-defined second-hand grip.

This is the whole story about how to saw, in fact, is presented, but now a postscript will be presented with a number of additions and amendments (plus a short retelling of the content of the vidos).

Sawing horizontally is inconvenient, because this requires that the workpiece be fixed at chest level and sawing while standing. However, workbenches, as a rule, are tables at which you need to sit, and if sawing, then standing and from top to bottom. Therefore, hacksaws are often made one-handed and sawed at an angle of 45 °.

To regulate the pressure on the saw (the harder the metal, the more you need to load the blade, press on it so that the teeth bite into the flesh; and vice versa. if the teeth cut too hard, for example, into aluminum, then you need to reduce the pressure) you can: a) change angle of inclination when sawing, b) put your hand on top to increase weight, c) unfold the blade with the teeth back.

The saw often gets stuck in the cut when it reaches the end of the bar. This is due to the fact that the blade has a wavy set of teeth (so that the cut is wider than the blade and it does not get stuck in the cut), but over time, in the center of the blade, the amplitude of this wave decreases, and at the ends. almost none.

This misalignment has arisen due to the sawing with this blade, previously not all of its length. It is no longer possible to correct (increase the dilution in the center or decrease at the ends), due to the fact that the teeth are hardened. So the moral: from the very beginning of the operation of a new blade, you must always saw through its entire length.

Next problem: if you cut a thin sheet of metal that is thinner than the distance between the teeth, the saw gets stuck:

If the metal is hard (iron), you will move the horseradish, and if it is soft (aluminum), a huge piece of metal is torn out, torn edges are formed, the edge bends.

Saw at an angle to form a kerf of such a length that at least two teeth lie on the kerf at the same time (kerf length ≥ two tooth spacing).

Next topic: sawing a thin-walled aluminum pipe:

We install the blade with the teeth back, twist the pipe in the direction of the teeth (otherwise the blade will get stuck at the near edge of the cut, and when force is applied, it will break).

Well, and even before the heap. a hacksaw blade for metal can be restored, the teeth can be sharpened, for example, in this way:

Initially, this diamond disk was larger in diameter and this drill with this disk, being pressed in this way to the blade, was located strictly parallel to the mowing line of the blade teeth, and the disk, respectively, was perpendicular. And it was right. the front edges of the teeth of the new hacksaw are orthogonal to the blade. Now a small negative angle is being formed. slightly less better, but also normal.

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 available in three main standard sizes:

Single, with a distance between the fixing holes 250 ± 2 mm, with a total blade length not exceeding 265 mm;
Single, with a distance between the fixing holes of 300 ± 2 mm, with a total blade length not exceeding 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 single version is 0.63 mm, double. 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. Such canvases can be easily distinguished by their color: ordinary steel canvases are dark gray, and dust-coated can have different colors. from bright orange to blue (depending on the manufacturer).

There are also canvases with the so-called tungsten carbide spraying, however, with a very high hardness, they are extremely sensitive to bending stresses. Therefore, when cutting metal, their durability is negligible.

The high strength of hacksaw blades for metal is ensured by appropriate heat treatment. On the surface of the blade, two zones are distinguished with different values of hardness: 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.

Hacksaw design for metal

The design of a mechanical hacksaw for metal includes a body and a file. The first consists of:

Frame on which the handle is installed to secure the canvas;
Saw tension adjuster (this part has a recess for inserting a replacement part and a screw with a nut, the rotation of which is tensioned).

Hacksaw blade for metal. How to choose and install?

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.

Hacksaw for metal how to put the canvas correctly. Principles for choosing 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 HCS designation on the lateral plane. High speed steel blades are suitable for cutting harder metals (corresponding import marking. HSS).
The thickness of the cut metal 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 it is required to obtain a very smooth cut surface, the PPI value is considered correct24. If for the user the main factor of productivity than quality, then there should be PPI

Hacksaw blade for metal. How to choose and install?

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 thin sheet metal cutting 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.Ox.Prm. Less commonly, you can find enamel-coated files. 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.

Types of hacksaw blades

Single, with a distance between the fixing holes 250 ± 2 mm, with a total blade length not exceeding 265 mm;
Single, with a distance between the fixing holes of 300 ± 2 mm, with a total blade length not exceeding 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 single version is 0.63 mm, double. 0.80 mm. Height with a single row of tines is 12.5 mm, and with a double row is 20 mm.

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.

Correctly install the sheet metal

Metal cutting is laborious, requires serious patience and requires good tools.

One of the most common tools is a hacksaw for metal. Basically, the type of hacksaws is about the same, the mechanism for changing the blade is different.

There are two widespread fastenings of the blade, this is a threaded clamp, while the blade is fixed and tightened with a special nut with a wing.

Another type of attachment is the linkage. In this case, the hacksaw blade for metal is removed and installed with the participation of a small lever.

In the latter case, according to the assurances of the manufacturers, the removal and installation of the web is faster. But the cost of such a hacksaw is much more expensive.

It’s hard to imagine a person who would work without stopping with a hacksaw all day, and the speed of changing the blade would be very important for him.

Therefore, the choice of a hacksaw attachment mechanism for metal depends solely on your desire, no more. Well, from the completeness of the wallet too.

There are plenty of hacksaw blades to this day. The choice primarily occurs between domestic and foreign manufacturers.

Domestic canvases do not differ in quality, they quickly become blunt, teeth fall out. But their cost is five, and sometimes fifteen times lower than foreign ones.

The canvases for metal are also distinguished as hardened and bimetallic. The latter are more flexible, less likely to break, but also more expensive than hardened ones.

Hacksaw blades differ in the number of teeth, they come with 18, 24 and 32 teeth.

To cut harder material, you need to take a blade with a large number of teeth, and vice versa.

If you take a metal blade with a small number of teeth for cutting hard material, it will be much more difficult to cut.

It is necessary to install the blade in a hacksaw for metal correctly, the teeth should be directed in the opposite direction from the working.

Only in this case, less effort will be spent on working with a hacksaw and cutting on metal will go easier and faster.

Product classification

Hacksaw blades are a narrow strip with two holes at the ends for attaching to the tool. There are three main criteria for their classification:

Purpose (for hand / electric hacksaws);
Manufacturing material;
Tooth parameters.

The division into groups according to the first criterion occurs as with hacksaws. they distinguish canvases for hand (mechanical) and electrical (sometimes called machine) tools. The sizes of the work items vary. So, for hand canvases, 250-300 mm long, 12-25 mm wide, 0.63-1.25 mm thick are used. An example is a domestic-made canvas made of X6VF steel with parameters 1.25x12x300, which will cost the buyer 30 rubles per piece.

Parameters of files for power tools vary from 150 mm in length, to 55 mm in width, from 1.25 to 2.5 mm in thickness. Example. a blade for a reciprocating saw HAMMER RS BL 001, the parameters of which are 150x19x1.25 mm, and per piece.

Another difference between saws for hand and reciprocating saws is the number of holes for fasteners. The first have two, the second have one.

Carbon (the least durable, suitable for non-ferrous or soft metals; marked as HCS); for example, Bosch HCS TF 350 M 408 mm GFZ for 1400 rubles;
High-speed (have the most wear-resistant teeth, but are fragile and expensive; HSS marking); Gross HSS 18TPI 300 mm. 160 rubles per pair;
Bimetallic blades (an innovation on the market, replacing analogs; the base is carbon steel, on top of which a high-speed strip is welded, serving as the basis for the teeth; denoted by BIM); Gross Variozahn 300 mm BIM from 300 rubles per pair.

There are also blades made of alloy steel (designation HM), but more often they are used for cutting brick, concrete or stone.

The size of the teeth for hacksaws for metal is 2-2.5 mm. This parameter is considered “small”, since there are products with a larger tooth (for example, for wood saws it is 4-6 mm).

International standardization provides for a different principle of dividing canvases. So, the number of teeth per 1 inch of the file is taken into account. This number is shown in the marking before the letters PPI (points per inch. “point per inch”) or TPI (formula “PPI. 1”). The higher the number, the smaller the tooth is represented on this blade.

When choosing products for a hacksaw, the user does not have to guess for a long time. most of the well-known files have a pitch of 18 or 24. This is how branded products for construction are indicated (for example, Standart 24 TPI 300 mm, Kraft-Flex 18 TPI blade from the manufacturer Kraftool).

The main classification of hacksaw blades for metal is based on the above criteria. It is important to know. the presence of set teeth is welcomed if the user expects comfortable work without pauses and tool breakages. Now about how to correctly install a hacksaw blade in a hand or power tool.

Types of hacksaw blades

Single, with a distance between the fixing holes 250 ± 2 mm, with a total blade length not exceeding 265 mm;
Single, with a distance between the fixing holes of 300 ± 2 mm, with a total blade length not exceeding 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 single version is 0.63 mm, double. 0.80 mm. Height with a single row of tines is 12.5 mm, and with a double row is 20 mm.

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.

Cutting the line with a hacksaw

A hacksaw for metal is also valuable in that it allows you to cut along almost any curve of the mowing line. To cut in an arc without interrupting the forward motion of the hacksaw, align it perpendicular to the end of the part material (i.e. 90 degree tilt angle) and gradually smoothly rotate the hacksaw arc 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 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, while using the side of the material that is external for the part to turn the blade.

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

Hacksaw blades

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. Experienced 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.

How to cut?

Since you were interested in the question of installing the blade, it means that advice on how to use a hacksaw for metal will not hurt. Grasp with one hand (right if you are right-handed or left-handed 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 canvas on the cut line. Guide the blade straight in the direction of the cut line. Keep the angle 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 emergency cases, for example, when turning the mowing line of the cut. The smoother the line you need to cut, 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 to 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 full force.

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 easily breaks 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.

How to properly and quickly saw with a hacksaw for metal?

To be honest, I don’t know any special secrets, but there are some nuances that should be observed.

About 30 years ago, when fortunes and angle grinders were not very much, whoever heard his father did all the work with metal with an ordinary hacksaw for metal. And a hand drill.

Firstly, I would advise choosing a hacksaw like in the second photo. This option is more convenient to work with. It’s just more comfortable to hold in your hands and the grip won’t slip in your hand.

When installing the blade, pay attention to the correct position of the teeth. As shown in the photo, they should go away from the cutter. When cutting, you need to apply force when the saw goes away from you. When returning the saw back, you need to slightly raise the handle and release the pressure on the saw itself. This way the teeth will stay in working order longer.

It is also worth paying attention to the tension of the blade when installing it in the saw. If the blade is too loose or too tight, then at the slightest hesitation of the saw it will simply break.

Well, so that the canvas does not get too hot, you can drop a couple of drops of oil into the area of the cut.

Well, do not forget that the metal that is cut can simply be broken. That is, sometimes it is enough to cut off half of, for example, a pipe or corner, and simply break the rest, by bending to one and the other side.

I would also like to draw your attention to the fact that the part that is supposed to be cut is desirable (if possible) to be securely fastened, for example, in a vice.

The author of the question chose this answer as the best

There are no secrets. You need to remember a few important points and the metal will scatter like butter on a knife.

You need to choose a saw with a comfortable handle and durable. We choose a canvas not from cheap ones, but with a durable composition sprayed on the teeth. Place the blade in the saw so that the teeth of the blade are facing away from you.

When performing a split, you need to actively apply force when moving the saw away from yourself and simply, without load, perform a movement from yourself. Try to cut with the blade position with the maximum contact area of the blade teeth with the surface of the object to be sawed or sawed. As for the split of the pipe, it is enough to cut the pipe to half and a little more, as it can break clearly under your little effort. Much depends on the thickness of the pipe and its age.

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As many colleagues have already noted, when performing work with a hacksaw for metal when cutting (sawing) it is necessary to pay attention to the following points:

Robust saw frame with a comfortable handle;
High-quality and appropriate step for a specific metal (depending on the viscosity and hardness of the metal) hacksaw blades;
Set the direction of the teeth away from you;
Hand movements should be smooth and with a wide amplitude.

As for the nuances, I can say that hacksaw blades are a material with high hardness and fragility and are afraid of overheating. Therefore, make constant stops at work and the saw will serve you for a long time.

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Your friend’s secret is not in the way of working with the instrument, but in the instrument itself. Handling a hacksaw for metal is taught at school (many made hammers, corners, etc.), therefore there are no special secrets: put the blade correctly and keep it straight when you saw. But in my practice there were special canvases for metal (I don’t remember exactly where: either from fur. Saws, or from some other machine, but not the essence.), Which lightly cut pipes in the apartment and other metal objects that are easier was to cut with a hacksaw than to spin an angle grinder for the sake of this business.

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I can offer several recommendations that will speed up cutting metal with a hacksaw:

Use a hacksaw with a sturdy frame made of composite materials.
For work, buying blades is better bimetallic, with hardened teeth.
For metals of different hardness, select a blade with the appropriate number of teeth:

For soft metals, the number of teeth should be minimal. 16-18 pcs / inch.

For hard metals. maximum (32 teeth by 25mm).

It is more rational to use new blades for cutting softer and more viscous metals (aluminum, brass, bronze, copper.), And used. for hard (steel, cast iron.)
If the blade breaks, it is imperative to clean the cut from any fragments of the blade that may have remained there and only after that continue working with a new blade.

By the way, if only one or a couple of teeth broke, the canvas can be saved from further destruction if you make an arc (notch) with rounded edges on emery (grind off) in this place.

A high pace of work does not always mean fast cutting of metal. There is a definite dependence of the number of back-and-forth movements on the hardness of the metal.

The harder the metal, the less intensity you need to work, otherwise the canvas will overheat and shrink quickly.

The position of the hacksaw, arms, body and legs is clearly demonstrated by this figure.

To learn how to quickly saw with a hacksaw for metal, you need to understand the following!

First, the hacksaw only cuts forward.

Second, in order for a hacksaw to cut metal, you need to apply even force when feeding the hacksaw forward and loosen it completely when pulling back.

Third. the movement of the hands should be as confident, uniform, as possible in an even plane (without swinging to the sides, blockages in the sides and forward backward, without twisting and jerking).

The fourth is the need to lubricate the hacksaw blade with machine oil from both sides, before starting sawing, and with significant cuts and applying lubricant to the blade as it develops.

Fifth, it is necessary to periodically water the cut so that it does not overheat and does not overheat the hacksaw blade, which can cause the hardening to be released and the blade will simply be erased.

Sixth. the metal that you are going to cut certainly matters, because not every metal can be easily cut with a hacksaw for metal, but there are those that cannot be cut at all, it is advisable to use a diamond cutting tool.

So these are the nuances. I hope there is no need to dwell on the choice and installation of the canvas, and in the previous answers this is already more or less described.

Hacksaw blade for metal. How to choose and install?

Sources:

http://bankingid.ru/metall/nozhovka-po-metallu-kak-pravilno-postavit-polotno.html

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