How to put a blade on a hacksaw

How to mount a metal blade correctly

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

Metal saw blades differ in width, length, thickness, spacing and height of the teeth. The use of one blade or another depends on the thickness, hardness and shape of the material to be cut. Blade manufacturers made sure you can choose a blade for the material you need to cut, be it aluminum, copper, bronze or even plastic. The blade dimensions, i.e. length, width, tooth size and steel grade, can be found on the hacksaw blade to be purchased.

How to set the blade in the metal hacksaw?

As shown in the first diagram in this article with the teeth facing down (if the blade is single sided) and the teeth pointing forward from the handle. When you saw, you apply downward and forward pressure. exactly the same way the teeth of the hacksaw should be pointing, down and forward. To install, loosen the tensioning screw, remove the old blade from its pins, put on the new blade, and tighten it so tight that the blade tinkles like a string when you snap your fingernail. Here the main thing is not to overdo it and not to break the blade. You will find the optimum tension by experimenting.

The tension is applied by means of the clapper on the adjuster, that is you will tighten the blade by twisting the clapper. So you have to find the golden mean when tensioning the hacksaw blade. Also, make sure that the blade is set flat and not twisted as twisting will cause an uneven cut during cutting.

How to Saw?

Since you were interested in the question about setting up the blade, it doesn’t hurt to have some advice about how to use a hacksaw on metal as well. Grasp the handle of the hacksaw with one hand (right hand if you are right-handed or left handed if you are left-handed) and with the other hand hold the vertical edge of the arc of the hacksaw opposite to the handle. Position blade on trimmer cut line. Guide the blade strictly in the direction of the cut line. Do not angle the saw blade too far back. The blade should rest almost on the piece, usually at an angle of 30-45 degrees. That way there will be less vibration, less noise and a smoother trimmer blade. Cutting across the material, with a 90 degree angle, is worthwhile only in urgent cases, such as when turning the cut line. The flatter you need your trimmer blade, the less of an angle you need.

The first movements should be done with little effort, so that the blade cuts into the material and does not slide sideways away from the cutting line. Making smooth, forward movements, press the hacksaw against the workpiece while moving forward and release pressure when returning to the starting position. When the blade grips the material. you can work with all your might.

Swing as far as possible, from blade edge to edge, without hitting the arc of the hacksaw against the workpiece. You don’t have to “tread on the spot”. that way you will quickly wipe the blade in one area and have to throw it away, because you can’t use a damaged blade. Keep the arc of the hacksaw straight, do not let it bow in any direction. The cutting direction corresponds to the arc plane of the hacksaw, so chattering is contraindicated here. Also, the blade breaks easily if the hacksaw jerks to the side. The material properties of the blade are such that it holds very well the longitudinal tensile force, but is very brittle in bending.

Cutting with a hacksaw on a curved line

A metal saw blade is also valuable in that it can cut almost any curve. In order to cut in an arc without stopping the forward motion of the hacksaw, align it perpendicular to the face of the part material (t.е. angle of 90 degrees) and gradually smoothly turn the arc of the hacksaw so that the blade follows the planned line. Yes, always make sure to mark the line for the trimmer cut with anything. pencil, marker, scratch nail. The main thing is to be able to see it when you work. Turning the blade should be done as gently and smoothly as possible, otherwise it will break; turns are an extreme for a metal hacksaw blade.

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

To cut the inside corner, you must first drill a straight line for the trimmer with a thin drill bit longer than the width of the blade, slide the blade into this groove and cut further with a hacksaw. Well, practice will show how it’s done. Nothing complicated here.

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

Hacksaw blades for metal

Metal hacksaw blades are one of the most unreliable elements of the whole range of consumables for tools. Of course, much 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 blade. Today, we will talk about the choice and types, as well as learn how to easily change a hacksaw blade.

Types of hacksaw blades

GOST R 53411-2009 “Metal hacksaw blades” specifies two types of such tools. for machine and hand cutting. We will not touch the first, and the latter are available in three basic sizes:

  • Single, with a distance between the fixing holes of 250±2 mm, with a total length of the blade not more than 265 mm;
  • Single, with the distance between the fixing holes 300±2 mm, with a total length of the blade not exceeding 315 mm;
  • Double, with the distance between the fixing holes 300±2 mm, with a total length of the blade not exceeding 315 mm.

In this case, the thickness of the blade s single version. 0.63 mm, double. 0.80 mm. The height with single tine row is 12,5 mm and with double tine row is 20 mm.

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GOST also regulates the pitch P, mm and number z of teeth, which for the first type are 0.80/32, 1.00/24 and 1.25/20 respectively. Owners of more “long” hacksaws, in addition to the 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, made of tool steels:

Assortment of hacksaw blades of domestic production is also limited by this fact, but in specialized trading networks so-called diamond blades with surface spraying by titanium nitrides or other refractory metals are commonly used. Such blades are easy to distinguish by their color: ordinary steel blades are dark gray, while the sprayed blades may have different colors ranging from bright orange to blue (depending on the manufacturer).

There are also blades with so-called tungsten-carbide sputtering, but they are extremely sensitive to bending stresses despite their very high hardness. Therefore when cutting metal their durability is insignificant.

High durability of metal saw blades is ensured by appropriate heat treatment. Two zones with different hardness values are distinguished on the surface of the blade: directly at the teeth it ranges from НRС 6467 for alloy tool steels to НRС 7378. for high-speed steels (for diamond blades this parameter reaches НRС 8284) and in the other zone. НRС 4446. Significant difference in hardness confirms the high sensitivity of the product to bending stress, so the standard also limits the maximum force applied to the hand hacksaw. It should not exceed 60 kg when working with blades, the tooth pitch of which is less than 1,4 mm, and 10 kg. for blades with tooth pitch over 1,4 mm.

Tool selection criteria

It is worth remembering that you should choose a metal saw in accordance with the recommendations, because mistakes can lead to the purchase of a low-quality product. Even minor defects reduce service life. The main criteria for selecting a tool for metal are in the following points:

The shape of the tooth is chosen depending on the slope of the cutting edge. In most cases, the classic shape is created in the production, as it is a universal option. A rather important parameter is the tooth pitch. Too much leads to lower productivity and higher cut quality. Many manufacturers list this parameter as one of the main ones, the value can vary in a very wide range. The length of the blade is chosen according to the size of the workpiece and the metal tool itself. This varies in the range from 300 to 700 mm

How to Choose the Right Hacksaw Blade

At the moment of choice one must pay attention that the surface has no essential defects. The product must recover its shape even after minor bending. The handle is available in many different versions

Do not give preference to products with a hollow handle, as it may break quickly. At the time of choice it is recommended to take the product in hand, it must be comfortable. The handle has recently been made of two materials, the combination of these materials ensures a long service life. Ribbing on the surface reduces the likelihood of slipping during operation. Type of material used for the main body. Most often an alloy is used, which is characterized by high resistance to moisture. This considerably increases the service life. The tensioning of the blade can be done in many ways. On the features of the mechanism used depends largely on the convenience of the device, as well as the service life of the blade used. When choosing, attention is also paid to functionality. As previously noted, some mechanisms allow for tilting the blade or changing the length of the cutting part.

Note that the metal saw is a basic tool. Even after the appearance of the angle grinder, it enjoys great popularity, as it can last for a long period and allows the treatment of hard-to-reach places. It is recommended to give preference to products of well-known brands, as it will last for a long period.

Hacksaw blades for handheld metal hacksaws. the right choice, types and installation

Metal hacksaw continues to be popular among handheld cutting tools.

The main advantage of this tool is that it can always be used when an electric tool is useless or its use is limited by the technological task.

To use a hacksaw, you will need to install a metal blade in the tool. Only before you install the cutting element, it is necessary to choose it competently.

Hacksaw blades for metal sawing tools

Consider hacksaw blades on metal should be considered from the fact that classify this type of consumable material into three types:

  • For hand hacksaws (they come in large and small). After the advent of the angle grinder or angle grinder, as well as circular, sabre saws and jigsaws, hand hacksaws have lost their popularity, but have not completely disappeared
  • For machine units. this includes band saw blades that are used in industrial settings (designed for the machine). Blades, having corresponding parameters: length, thickness, material of production, sharpness and form of teeth, are used for band saws. At home these machines are only used when high-precision cutting of metal parts is needed. These units use special bandsaw blades, the teeth of which are sprayed with carbide materials. Band saws not only use tools for metal cutting, but also for wood. Band saw blades require additional water cooling during operation, which extends the life of the units and reduces the load on the drive mechanisms of the machine units
  • Stand-alone electric units are the tools that have supplanted handheld hacksaws. These include sabre saws and jigsaws. For sabre saws, blades of appropriate shapes and technical parameters are available. For jigsaw blades on metal also have the appropriate parameters, so when choosing them, it is important to consider for what type of tool the consumable cutting materials are intended

In this material we will consider in detail the metal blades for hand hacksaws, which you can buy in any construction store, on the market and even in online stores. By the way, the advantage of buying on the Internet is that the buyer has a wide range of choices, unlike buying in a store, where the range is limited to two or three models.

Types of cutting tools for metal hacksaws

Cutting accessories for handheld metal saws are available in three types:

  • Single. have a total length of blades up to 265 mm. However, the main parameter on such equipment is the distance between the fixing holes, which is 250 mm
  • Single standard are the most popular models of blades, which have cutting teeth only from one part. The spacing between the fixing holes is 300 mm and the total length of the blade is up to 315 mm. If you buy hand saw blades, then you should consider (measure) not the total length of the blade, but the distance from one attachment hole to another. Usually, manufacturers indicate the dimensions on the side of the tooling
  • Double. fully identical to the previous type in size, only cutting parts on such devices are located on both sides. This allows you to increase the service life of the headset, because if the teeth on one side are worn and blunted, you need to turn the blade, and continue to use it

Hacksaw Basics: How to buy and use a hacksaw.

Single blade metal blades have a thickness of 0,63 mm, double blades have a thickness of 0,8-1,25 mm. On the headset this parameter is marked with the letter S. There is also a difference in blade width or height. For single set the height is 12,5 mm and for double set the height is 20-25 mm.

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GOST R 53411-2009 regulates such main indices as pitch of teeth and their quantity that are marked with the letters P and Z. These indicators affect the quality and speed of cutting of metal parts and workpieces. The length of the devices in question are also 150, 350 and 400 mm.

What are they made of

Modern hacksaw blades for metal are made of the following types of steel:

blade, hacksaw
  • Carbon steel. they have low hardness, so they can be used for cutting non-ferrous and soft metal. This class of headset is marked HCS, and the degree of strength does not exceed the values of 44-46 HRC.
  • Fast-cutting. have high resistance to abrasion and tooth wear, but their disadvantage is brittleness. Speed-cutting saws are marked as HSS and have the hardness degree up to 73-78 HRC. There are high-speed steel blades with diamond cladding that have hardness level up to 82-84 HRC. apiece
  • Bimetal. so called because two kinds of steel are used. Their production has created a furor on the market, quickly ousting their analogues. Bimetal blades are based on materials such as carbon steel, onto which a high speed steel strip is welded. These types of devices are designated by the letters BIM, and their strength is the same as that of high-speed steel, only due to the use of carbon steel as the basic material, they have high strength and resistance to deformation
  • Alloy tool steels are upgraded versions of their carbonaceous counterparts, and are produced by augmenting the carbon with chromium, tungsten, vanadium, silicon, etc.п. Alloying makes it possible to reach high strength parameters and the hardness level is a little bit lower than that of high speed steel, i.e. 67-67 HRC.

The hardness of a hand saw blade characterizes the sensitivity of the tool to bending stress, so depending on the cutting devices used, you must consider the force exerted on the hacksaw during operation.

Usually the blade force should not exceed 60 kg, which is characteristic for saw blades with tooth pitch less than 1.4 mm. If the pitch of teeth is more than 1,4 mm, then the load must not exceed 10 kg.

How to choose correctly a blade for metal saws

Sawing equipment in the form of consumables for hand hacksaws should be selected on the basis of such indicators:

Types of hacksaw blades

GOST R 53411-2009 “Hacksaw blades on metal” establishes two types of such tools. for machine and manual cutting. We will not touch the first, and the 2nd are available in three main sizes:

  • Single, with a distance between the fastening holes 250±2 mm, with a total length of the blade less than 265 mm;
  • Single, with the distance between the fixing holes 300±2 mm, with a total length of the leaf less than 315 mm;
  • Double, with the distance between the fixing holes 300±2 mm, with a total length of the leaf less than 315 mm.

In all this the thickness of the blade s single performance is 0,63 mm, double. 0,80 mm. The height with a single row of teeth is 12.5 mm and with a double row of teeth it is 20 mm.

GOST also regulates values of tooth pitch P, mm and their quantity z, which are 0,80/32, 1,00/24 and 1,25/20 accordingly for the first type blades. Owners of the “longer” hacksaw blades, in addition to those listed above, can also use hacksaw blades with the parameters of 1.40/18 and 1.60/16.

According to the grade of material used for the production of hacksaw blades for metal, they are made of tool steels:

blade, hacksaw

Assortment of the Russian-made hacksaw blades includes only those, but in specialized trading networks so called diamond blades with surface spraying by titanium nitrides or other high-temperature metals are widely spread. Such cloths can be distinguished by its color: ordinary iron cloths are dark gray, and the sprayed ones may have different colors. from bright orange to blue (depending on manufacturer).

There are also blades with so-called carbide-tungsten sputtering, but they are very sensitive to bending stress. That’s why their durability is insignificant when cutting metal.

High durability of metal saw blades is ensured by an appropriate thermal treatment. Two zones with different hardness values are distinguished on the surface of blade: specially near the teeth it ranges from НRС 6467 for alloyed tool steels to НRС 7378. for high-speed steels (for diamond blades this parameter reaches НRС 8284), and in the other zone. НRС 4446. Significant hardness difference confirms high sensitivity of the product to flexing stresses, that’s why the biggest effort applied to the portable hacksaw is also limited by this standard. It must not exceed 60 kg when working with blades, the tooth pitch of which is less than 1,4 mm, and 10 kg. for blades with the tooth pitch over 1,4 mm.

Blade for metal hacksaw. How to choose and how to put?

Types of hacksaw blades and their design

Do not forget about the fact that the production of the working hacksaw blade is carried out in accordance with the established standards in GOST 53411-2009.

blade, hacksaw

The information specified in this normative and technical documentation determines the allocation of two main groups: for machine cutting and manual cutting.

It is worth considering that the machine saw blade on metal is purchased very rarely, as such equipment is used very rarely. The following versions are produced for the hand hacksaw:

  • Single hacksaw blade for metal with a distance between the fixing elements of 250 mm. The total length is 265 mm. This version is suitable for tools which are used when there is no need for high output.
  • Single versions with a distance of 300 mm between the two fixing elements. Total length is 315 mm.
  • For higher productivity, a double hacksaw blade is installed. The length of this version is the same as the previous one.

When selecting, attention is also paid to the width, which is 0.63 mm for the single version and 0.8 mm for the double version. The tooth height in the first case is 12,5 mm, in the second 20 mm.

The value of the pitch is also regulated, since such a parameter determines many performance characteristics.

A variety of alloys can be used in the manufacture of such a product, which largely determines the main performance characteristics. The following alloys are the most widely used:

Hacksaw blades with tungsten carbide sputtering have recently become quite common, as they are characterized by increased wear resistance. It is worth considering that the sputtering can have the most different colors, on sale there are blue variants of execution, the usual steel is dark gray.

The considered tungsten hacksaw blade is characterized by the fact that at high hardness of the working surface the structure is characterized by high sensitivity to bending load. That’s why if metal is cut carelessly, such a product cannot be used for a long time.

Manufacturers are able to achieve a high strength index through heat treatment. The following should be taken into account:

  • The main part of the product is characterized by hardness of the surface layer of about HRC 44-46.
  • Depending on the type of material, the hardness of the tooth varies in the range of HRC from 64 to 67. This value is characteristic of alloyed alloys. High-speed steel is characterized by the fact that it has a hardness HRC in the range of 73-78 units.

It should be remembered that considerable variations in hardness make the product sensitive to bending. The tool is designed for different loads, it should not exceed 60 kg at a pitch of 1.4 mm, as well as 10 kg at a pitch of less than 1.4 mm.

quite a large number of varieties of such a product determines that the selection of a suitable performance variant does not cause serious problems.

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What are made of

Modern hacksaw blades for metal are made of the following types of steel:

  • Carbon steel. have low strength characteristics, so they can be used for cutting non-ferrous and soft metal. This type of steel is marked HCS, and the degree of strength does not exceed the values of 44-46 HRC.
  • HSS. have high resistance to abrasion and tooth wear, but their disadvantage is brittleness. Speed-cutting saws are marked with HSS designation and have hardness level up to 73-78 HRC. There are blades of high-speed steel with diamond coating, which have hardness up to 82-84 HRC. per piece
  • Bimetallic. received this name because of the use of two types of steel. Their production created a furor on the market, quickly ousting their analogues. Bimetal blades are based on materials such as carbon steel on which a high-speed steel strip is welded. These types of devices are designated by the letters BIM, and their strength is the same as that of high speed steels, but due to the use of carbon steel as a basic material, they have high strength and resistance to deformation
  • Alloy tool steels are modernized models of carbon analogues, which are made by alloying carbon with chrome, tungsten, vanadium, silicon, etc.п. Alloying allows high strength values to be achieved and the hardness is slightly lower than that of high speed steel, ranging from 67-67 HRC.

The hardness of the handheld sawing set characterizes the sensitivity of the tooling to bending stress, so depending on the cutting devices used, it is necessary to consider the force applied to the hacksaw during operation.

Generally, the maximum force is 60 kg, which is characteristic of tools with a tooth pitch of less than 1.4 mm. If the tooth pitch is greater than 1.4 mm, the load must not exceed 10 kg.

Principles of blade selection

It is important to choose the most suitable version of the product for the specific operating conditions. If the surface does not have the required properties, it will not last over the long term. The selection criteria are as follows:

  • The most important selection criterion is the distance between the two fixing holes. With some tools, this can be changed by a special device.
  • The next selection criterion is the strength of the metal to be cut. If the work involves cutting of common soft alloys, e.g. copper or aluminium, choose a product with the lowest surface hardness. X6VF steel is very common, with imported blades using the HCS designation. Also, you can perform processing of strong metals, which is suitable for hacksaw blades made of high-speed steel, imported marking HSS,
  • Also takes into account the thicknesses of metal being cut and the quality to be achieved after machining. Internationally, PPI. the number of tooth tips per inch of length. is becoming the decisive criterion. High quality requires a PPI greater than 24, if productivity is the priority, then a version with less than 24 is chosen.
  • When selecting, the quality of the cutting edge spreading is taken into account. This parameter must meet the specifications given in the above GOST. There are three basic models: each one, one tooth or two adjacent ones.

Grinding the band saw blade

Just as a new car needs a running-in period, a new band saw blade needs to be lapped by cutting. It is necessary if the standard mode of movement of the blade is 30 meters per minute or more. The blade should run for about 1000 square centimeters at a lower load than in the standard cutting mode.

If no or insufficient lapping is carried out, then the cutting edges of the teeth are not yet levelled. In this case, problems such as vibration, chipping, or uneven wear can occur. The blade life and quality of the blade may be significantly impaired.

In order to perform a proper lapping by cutting, it is necessary to:

Set the blade speed to 30 meters per minute and calculate the cutting time from the chart below. For example for a section width of 200 mm. The cutting time will be 16 minutes. Set the cutting speed so that the required cutting time is reached. Setting is carried out using the “,-” buttons on the rocker switch speed regulator. Keep cutting force at a fixed level that is set in the standard cutting mode.

blade, hacksaw

Step by step increase the speed of the blade and the cutting speed until the standard cutting mode is reached. The number of cuts required for lapping by cutting is calculated as follows: The required lapping area must be divided by the cross-sectional area of the material to be cut.

Lapping by cutting is complete when the lapping area defined for the blade and material is reached.

The specified cutting lapping regimen should be taken as a guideline. It may be necessary to individually select a cutting mode that eliminates rattling or vibration during the initial cutting period.

Metal hacksaw. how to choose and install the blade correctly

Cutting metals is a labor-intensive activity that requires a lot of patience and good tools.

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

Two attachments of the blade are common, it is a threaded clamp, the blade is fixed and tensioned by a special nut with a wingnut.

Another type of mounting is the lever mechanism. Hacksaw blade on metal in this case is removed and installed with the help of a small lever.

In the latter case, according to the assurances of the manufacturers, the removal and installation of the blade is faster. But the price of such a hacksaw is also much higher.

It’s kind of hard to imagine a person who would work all day long with a hacksaw, and the speed of blade replacement would be very important for him.

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

Blades for hacksaw blades on this day is enough. The choice is primarily between domestic and imported manufacturers.

Domestic blades are not of high quality, they get blunt quickly, teeth fall out. But their price is five and sometimes fifteen times lower than the foreign ones.

Also differentiate between metal blades as hardened and bimetallic. The latter are more flexible, less likely to break, but also more expensive.

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

harder material requires a blade with more teeth and vice versa.

If you use a metal blade with fewer teeth to cut harder material, it will be much harder to cut.

Set the blade in the metal hacksaw correctly, the teeth should be directed in the opposite direction from the working.

Only in this case on work with a hacksaw will be spent less force and metal cutting will go easier and faster.

Number of teeth

Number of teeth per inch is the deciding factor. The following depends on it:

  • Performance is determined by the number of teeth. If you increase the number of cutting edges, the task becomes much more difficult, the chips become finer.
  • Large quantity allows you to get a quality cut. This is achieved by reducing the size of the cuttings.

In addition, an increase in quantity leads to an increase in the cost of the product.

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