How to insert the blade into the hacksaw. How the cut is made?
How to choose and install a blade for a metal hacksaw. Installation of the blade on the metal hacksaw
Hacksaw blades for metal refers to those parts that are the fastest in disrepair and require frequent replacement. However, knowing the intricacies of product selection can ensure long and high-quality work!
Universal saw. hacksaws for all occasions
Even an ordinary, at first glance, hacksaw can cause confusion to the average consumer, on the shelves he will find many different tools from each other! To simplify the choice, let’s list the three main types of tools into which, depending on their purpose, they are divided:
- Metal hacksaws. a narrow saw with thin teeth. Has a characteristic recognizable appearance, mainly a C-shaped or U-shaped frame, between the ends of which the blade is tautly fastened. Old models of hacksaws often have a handle that runs parallel to the blade, modern products are equipped with a much more ergonomic “pistol” handle.
- A wood saw is a classical joiner’s tool that is used for cutting wooden building materials as well as sheets of plywood. As a rule, joiner’s hacksaws have a wide beveled working part with cutting teeth on the edge. The teeth are bifurcated alternately to the left and right to facilitate cutting. At the same time, the straight teeth in some models help remove chips from the cutting line.
- A concrete hacksaw is externally similar to a joiner’s saw, with the difference that the first tool has larger teeth. Quite often they have the tips of hard-alloy metal, so this tool can saw foam blocks and sand-concrete structures.
The quality of the tool is determined by the following indicators:
- Length of the blade. depending on the size of the workpiece the appropriate tool is selected. On average, the length of the working part ranges from 300-700 mm.
- Tooth pitch. this factor determines the thickness and hardness of materials that the tool can handle. For example, a 3.5mm pitch is good for cutting soft wood, while 5mm is for cutting harder wood.
Metal hacksaw. cutting steel in house slippers!
With the advent of metal hacksaws, working with various metal products has become much easier. even at home, in your garage or workshop you will be able to saw off the desired piece of rebar or thick wire. And even the appearance of mechanical counterparts has not affected the popularity of hand tools: firstly, the cost is affordable to almost any craftsman, secondly, during the work high accuracy is achieved, thirdly, the tool is almost impossible to break, and fourthly, the independence of the product on the power supply makes it indispensable in the field work.
Modern hacksaws differ not only by their “pistol grip”. manufacturers invent and improve blade fastening systems. The threaded clamp, present in all older models, has been gradually replaced by a lever mechanism that allows you to install the blade many times faster. True, they are also more expensive than hacksaw blades with a “wingnut”.
However, the design features influence by and large only on the convenience of tool maintenance, cutting quality and speed of work depend primarily on the replaceable hacksaw blades. They are plenty on sale, you can find a product for any purse and any purpose. The cost of blades depends on the alloy they are made of and the number of teeth per inch. Mostly there are parts made of hardened steel and bimetal products. The disadvantage of tempered steel is its brittleness, so these products though cost cheaper, but also break more often, while bimetal steel boasts good flexibility and hardness, so they cost more.
Choosing a hacksaw for metal. don’t overpay!
Even a tool as simple as a metal hacksaw should be chosen knowledgeably. Remember that your salesman’s job is to sell you the most expensive tool possible, but you will hardly use more than 10% of its capabilities. Use the golden mean rule. avoid budget models and do not buy the most expensive ones. It must be practical, with different angles of operation and different blades.
The popularity of some models is due to the ability to work with blades of any length, and this is really a very good move. Also note the ability to change the angle of the blade in the frame itself, a feature that allows you to work on metals, even in hard-to-reach places. Hold the tool in your hands, grasp the handle in the palm of your hand. The palm of the hand must fully encompass the handle, and the fingers must not interfere with each other and must not rest on the workpiece. Avoid hollow handles. a slight squeeze will break the tool. The product should not be loose, all parts fit together and give a feeling of reliability.
Metal hacksaw blades. a knowledge-based choice!
When buying a blade pay attention first of all to its appearance. even the smallest flaws can affect its performance. Avoid blades with traces of corrosion, cracks or roughness. An ideal blade should be smooth, clean, evenly toothed, and, when bent, instantly restore its original shape. The more teeth per inch you have, the faster you can cut your workpiece. For example, there are blades with 18 and 24 teeth per inch that are most often bought for home use, but 32 teeth per inch is for professionals.
Avoid buying black products. these last for several runs, then the crumbled teeth make the work impossible. Although not flexible, but it is much more convenient to work with them. In appearance, these look like a nickel-plated strip of stainless steel metal with dark teeth. it is by the color of the teeth that it is easiest to guess about their hardening. Bimetal blades are usually painted in some colors and though they cost more, they last much longer. Once you have chosen the right material, be sure to match the length of the product to the length of the hacksaw.
Using the tool. patience and work will overcome everything!
Metal hacksaw does not require any special skills in operation. You will only have to monitor the condition of the blade and change it in time. By the way the small toothing of the tool is not only suitable for working with metal, it is also good for sawing foam plastic, chipboard, PVC, laminate and even ceramics and plexiglass. The cut edges will be pretty straight.
Metal hacksaw blades: types, construction, choice
Metal hacksaw is considered a fairly common hand tool, which is designed to divide the workpiece into several separate parts of a certain size. Its design features are characterized by the fact that there is an opportunity to conduct periodic replacement of the working blade. When machining metal, there is a very high probability of rapid wear of the cutting edge. That’s why the function of changing the band was provided, which requires a small amount of time. There is simply a huge number of different blades, let’s consider the peculiarities of choice and many other points in more detail.
Saws blade types and their design
It should be remembered that production of working hacksaw blades is carried out in accordance with the standards of GOST 53411-2009. The specified information in this normative and technical documentation determines the allocation of two main groups: for machine 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 designs are produced for the hand hacksaw:
- Single saw blade for metal with a distance between the fixing elements of 250 mm. The total length is 265 mm. This version is suitable for the tool, which is used when there is no need for high output.
- Single version with distance between two clamping elements 300 mm. Overall length is 315 mm.
- Double hacksaw blade is installed for greater productivity. The length of this version is the same as the previous one.
When selecting, attention is paid to the width, which is 0,63 mm for the single version and 0,8 mm for the double version. Tooth height in the first case is 12.5 mm, in the second 20 mm.
How to Choose the Right Hacksaw Blade
Regulated value and spacing, as such an indicator determines many of the performance characteristics.
When manufacturing such a product, very different alloys can be used, which largely determines the basic performance characteristics. The following alloys are the most common:
Hacksaw blades with tungsten carbide coating have recently become quite popular, since they are characterized by high 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 tungsten hacksaw blade under consideration is characterized by the fact that at high hardness of the working surface the structure is characterized by high sensitivity to bending load. That is why if metal is cut carelessly, such a product will not be able to last for a long time.
Manufacturers can achieve a high degree of durability by heat treatment. At the same time it is worth considering the following:
- The main part of the product is characterized by the hardness of the surface layer of about HRC 44-46.
- the hardness of the tooth ranges from 64 to 67 HRC, depending on the type of material used in the making. This is characteristic of alloyed alloys. High-speed steel is characterized by the fact that its HRC hardness is in the range of 73-78 units.
Do not forget that significant 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 tooth pitch of less than 1.4 mm.
A rather large number of varieties of such a product determines that no serious problems arise with the selection of a suitable version.
Principles of blade selection
It is important to choose the most suitable workmanship for the specific application. If the surface does not have the required properties, it will not last for a long period of time. The selection criteria are as follows:
- The distance between the two attachment points is the most important selection criterion. With some tools, this index can vary thanks to a special device.
- The next selection criterion is the toughness of the metal being cut. If the work involves cutting of common soft alloys, such as copper or aluminum, choose a product with the lowest hardness of the surface layer. X6VF steel is very common, imported HCS designation is applied to the blades. It is also possible to carry out processing of strong metals, for which the saw blades made of high-speed steel, imported marking HSS are suitable,
- The thicknesses of the metal to be cut and the quality to be achieved after machining are also taken into account. Abroad, the decisive criterion is PPI, which is the number of tooth tips per inch in length. For high quality requires a PPI greater than 24, but if performance is the priority, then the version with less than 24 is the right choice.
- When selecting, attention is paid to the quality of the cutting edge. This parameter must comply with the norms stated in the above GOST. There are three basic designs: one toot each, one toot each, or two adjacent to each other.
Many people look for a hacksaw blade that will last for a long time. Note that the service life is influenced by the quality of the coating applied. The use of inexpensive substances becomes the reason why a large number of cracks appear on the surface when heated.
The quality is also influenced by the evenness of the set. A good metal hacksaw blade has a deviation of max. 45% on a length of 10 mm. The visual inspection also makes it possible to determine whether the individual tines are equal in height. Precise results can be obtained using a micrometer or other precision measuring instrument.
How to install the blade on a hacksaw for metal
The design of the tool in question allows for quick change of the hacksaw blade. It is worth bearing in mind that if a mistake is made, the product in question will not last for a long period of time. How to install a blade in a hacksaw for metal. a very common question, as this tool is found in almost all home workshops. The main recommendations are as follows:
Cutting metal with a hacksaw
You need to learn how to properly install the hacksaw blade in the machine, master holding the hacksaw, cutting bar, square, strip metal, pipes and angles on the markings and without turning the hacksaw. Needed: a parallel vice, flat wooden blocks, pads, triangular files, chalk, oil. Tool: hacksaw, blades for it.
Hacksaw, proper and improper blade setting
Blades on hand hacksaws for metal. the right choice, types and installation
Among handheld cutting tools, the metal hacksaw continues to enjoy popularity.
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 installing the cutting element, it is necessary to choose it correctly.
Metal hacksaw blades for saw tools
Consider hacksaw blades for metal should be considered with the fact that classify this type of consumable material into three types:
- For handheld hacksaw blades (they come in large and small). After the advent of the angle grinder or angle grinder, as well as circular saws, sabre saws and jigsaws, hand hacksaws have lost their popularity, but have not disappeared completely
- For machine units. these include band saws, which are used in industrial conditions (designed for the machine). For band saws, blades with the appropriate parameters are used: length, thickness, material of manufacture, sharpening and shape of the teeth. At home, such units are used only when high-precision cutting of metal parts is necessary. Such units use special bandsaw blades, the teeth of which have a coating of hard-alloy materials. Band saws are not only equipped for metal cutting, but also for wood. Bandsaw blades require additional water cooling during operation, which extends the life of the devices 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 jigsaws and jigsaws. For sabre saw blades of corresponding shapes and technical parameters are available. For the jigsaw blades for metal also have the appropriate parameters, so when choosing them, it is important to consider what type of tool the consumable cutting materials are intended for
In the material we will consider in detail the metal blades for hand hacksaw, 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 greater choice, as opposed to buying in a store, where the range is limited to two or three models.
Types of cutting accessories for metal hacksaws
Cutting accessories on handheld metal saws are available in three types:
- Single. have total length of blades up to 265 mm. However, the main parameter on such tools is the distance between the fixing holes, which is 250 mm
- Single standard are the most popular models of blades that have cutting teeth on one side only. 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, you should consider (measure) not the total length of the blade, but the distance from one fixing hole to the other. Usually manufacturers indicate the dimensions on the side of the jigs
- Double. fully identical to the previous type in its dimensions, only the cutting parts on such devices are arranged on both sides. This allows to increase the service life of the headset, because in case of abrasion and blunting of teeth on one side, it is necessary to turn the blade over and continue its use
Metal blades of single version have thickness of 0,63 mm, and double ones have thickness of 0,8-1,25 mm. On the headset, this is indicated by the letter S. There is also a difference in width or height of the blades. For a single set, the height is 12.5 mm, and for a double set, the height is 20-25 mm.
GOST R 53411-2009 regulates such main indices as pitch and number of teeth, which are designated by the letters P and Z. These values have an impact on the quality and speed of cutting of metal parts and workpieces. The devices in question are also available in lengths of 150, 350 and 400 mm.
What are they made of
Modern metal hacksaw blades are made of the following types of steel:
- Carbon steel. they have low strength properties, so they can be used for cutting non-ferrous and soft metal. Blades of this class are marked HCS, and the degree of strength does not exceed the values of 44-46 HRC.
- High-speed cutting. have high indicators of resistance to abrasion and tooth wear, but their disadvantage is fragility. HSS saws are marked HSS and have a hardness rating of up to 73-78 HRC. There are diamond-powdered high-speed steel blades that have a hardness rating of up to 82-84 HRC. apiece
- Bimetal. received this name because of the use of two types of steel. Their production has created a furor on the market, quickly supplanting their counterparts. Bimetal blades are based on materials such as carbon steel, onto which a strip of high speed steel is welded. These types of devices are designated by the letters BIM, and their strength is the same as that of high-speed steel, but due to the use of carbon steel as a base material, they have high strength and resistance to deformation
- Alloy tool steels are upgraded models of their carbon counterparts, which are made by alloying carbon with chromium, tungsten, vanadium, silicon, etc.п. Alloying allows you to achieve high strength values, and the degree of hardness is slightly lower than that of high-speed steel, and is 67-67 HRC.
The hardness of the handheld sawing equipment characterizes the sensitivity of the tooling to bending stress, so depending on the cutting equipment used, it is necessary to consider the force exerted on the hacksaw during operation.
Usually the force value should not exceed 60 kg, which is characteristic for hacksaw blades with tooth pitch equal to less than 1.4 mm. If the tooth pitch is more than 1,4 mm, the load should not be more than 10 kg.
How to choose the right blade for a hacksaw for metal
Sawing equipment in the form of consumables for hand hacksaws should be selected on the basis of such indicators:
Blades on hand hacksaws on metal. the right choice, types and installation
Among handheld cutting tools, metal hacksaw continues to enjoy popularity.
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 installing the cutting element, it is necessary to choose it competently.
Metal hacksaw blades for sawing tools
To consider a hacksaw blade on metal, it is necessary to consider the fact that classify this type of consumable material into three types:
- For handheld 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, handheld hacksaws have lost their popularity, but at the same time have not completely disappeared
- For machine units. these include band saws that are used in industrial settings (designed for the machine). For band saws are used blades that have the appropriate parameters: length, thickness, material of manufacture, sharpening and shape of the teeth. At home, such units are used only when it is necessary to carry out high-precision cutting of metal parts. For such tools, special bandsaw blades are used, the teeth of which have a coating of hard-alloy materials. Band saws not only use tooling for cutting metal, but also wood. Band saw blades need additional water cooling during operation, which extends the life of the units and also reduces the load on the drive mechanisms of the machine units
- Stand-alone electric units are the tools that have replaced handheld hacksaws. Such tools include sabre saws and jigsaws. For the sabre saw blades of corresponding shapes and technical parameters are available. For jigsaws blades for metal also have relevant parameters, so when choosing them, it is important to consider what type of tool the consumables are designed for
In the material in detail consider the metal blades for hand hacksaw, 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, as opposed to 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 tooling is the distance between the fixing holes, which is 250 mm
- Single standard. these are the most popular models of blades that have cutting teeth on only one part. The space between the fixing holes is 300 mm, and the total length of the leaf is up to 315 mm. If you buy a blade for manual saws, then consider (measure) not the total length of the blade, but the distance from one mounting hole to another. Manufacturers usually indicate dimensions on the side of the tooling
- Double. fully identical to the previous type in size, only the cutting parts on such devices are located on both sides. This allows to increase the service life of headsets, because in case of abrasion and blunting of teeth on one side, it is necessary to turn the blade and continue its use
Metal blades of single version have a thickness of 0.63 mm, while the double version has a thickness of 0.8-1.25 mm. On the headset this parameter is indicated by the letter S. There is also a difference in width or height of the blades. For a single headset, the height is 12.5 mm, and for a double headset, the height is 20-25 mm.
GOST R 53411-2009 regulates such basic indices as pitch and number of teeth, which are designated by the letters P and Z. These indicators affect the quality and speed of cutting metal parts and blanks. The length of the examined devices is also 150, 350 and 400 mm.
What are they made of
Modern blades for metal hacksaw is made of the following types of steel:
- Carbon steel. they have low strength properties, so they can be used for cutting non-ferrous and soft metal. This grade is marked HCS, and the degree of hardness does not exceed 44-46 HRC.
- High-speed-cutting. have high resistance to abrasion and tooth wear, but their disadvantage is brittleness. High-speed saw blades are labeled HSS and have hardness levels up to 73-78 HRC. There are blades of high-speed steel with diamond coating, which have hardness level up to 82-84 HRC. per piece
- Bimetallic. so-named because two types of steel are used. Their production created a furor on the market, quickly replacing their analogues. Bimetal blades are based on materials such as carbon steel on which a high speed steel strip is welded. Denoted by the letters BIM, these types of devices are the same as fast-cutting, only due to the use of carbon steel as the 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 makes it possible to achieve high strength properties, and the hardness degree is slightly lower than that of high-speed steel and amounts to 67-67 HRC.
The hardness of the handheld sawing accessories characterizes the sensitivity of the accessories to bending stress, therefore, 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 typical for tools with tooth pitches under 1.4 mm. If the tooth pitch is greater than 1.4 mm, the load should not exceed 10 kg.
How to choose a proper band saw blade for metal
Sawing equipment in the form of consumables for hand hacksaws should be selected based on such indicators:
How to insert the saw blade into the hand jigsaw
As a rule, there are far fewer problems associated with the use of an ordinary hand jigsaw than with its more advanced, electric counterparts. Anyway, there are several useful recommendations for this tool, some of which concern the installation of the saw blade. Let’s be clear about how to properly insert the saw blade into the hand jigsaw without complicating the further sawing process.
The first thing to look at is the very location of the saw tails at the attachment points. For the best adhesion, the tails of the saw should not be clamped at the edge or behind the screw, but 1-2 mm in front of it, as indicated in the image above. Before installation, remember that the teeth of the blade are always directed towards the handle, as sawing takes place when the tool moves downward.
First, the edge of the saw should be fixed at the handle. Next, you need to gently squeeze the edges of the arc and tighten the other end of the blade in the opposite mount. To do this, you can rest the tool against the edge of the workbench and press it with your chest. Insert the saw into the slots with one hand and tighten the thumbscrew with the other. If the size of the fasteners does not allow you to securely fix them by hand, you can slightly tighten with a pair of pliers. The main thing is not to overdo it, so as not to break the thread.
For jigsaws with a tubular arc, there is a special device, which, in most cases, is part of the sawing table. This product is 2 round slots located on the edge of the board. The tool is inserted into the recesses, and then the saw is quietly tightened in the clamps. To learn how to insert the saw into the jigsaw in more detail, see the video below.
What kind of plywood is needed for sawing with a jigsaw??
Practice shows that the best material for working with a hand jigsaw is birch plywood 2 to 8 mm thick. It is affordable, easy to handle and highly durable.
To create small details or “dense” openwork pattern, it is more appropriate to use three-layer plywood up to 3 mm thick. It can be easily sawn and is quite strong. The probability that you will spoil the sawed curl at the next jamming of the blade is significantly lower.
Choosing the material for the crafts, pay attention to the fact that the plywood was even and without a large number of knots. Examine the end face for air chambers, their presence indicates an uneven application of glue. From such low-grade plywood is better to refuse, otherwise you can not avoid a large number of chips, which will spoil the appearance of the product.
Read also: How to repair soldering iron at home
Hacksaw blades: the choice for the materials to be processed and their classification (105 photos)
When cutting the material we use different types of hacksaws. The most important component, on which the quality of work depends, is the blade. It is the blade that gets the job done, but it is also the one that has the most exposure, which results in frequent breakage. In this article we’ll tell you how to pick up a blade for a hacksaw and what to pay attention to.
Selection of blade by material to be machined
It is possible to cut a variety of materials. wood, metal, drywall, plastic, etc.д. For different types of workpieces are used:
Metal hacksaw blades. made of strong materials, depends on the strength limit factor of the workpiece being sawn. On the plate itself the teeth can be set in a “tooth over tooth” or “two adjacent over one” manner.
Carpenter’s hacksaws feature an expanded beveled work surface. The teeth are mounted on the edge and are alternately set in different directions. The presence of straight teeth is associated with the possibility of removing shavings during work.
Blade on concrete. has similarity with carpentry tools. However, the teeth here are larger and have hard metal tips.
Classification of hacksaw blades for metal
Such a product is easily identified by the presence of two holes on the edges for fastening to the base. Despite the fact that such a strip is quite narrow, its durability is not in doubt, although it requires periodic replacement.
Blades can be intended for use as part of a hand-held tool or for attachment to mechanical units. in this case the type of tool influences the dimensional characteristics of the replaceable cutting equipment.
Its length in mechanical tools can be in the range of 250-300 mm, and width. 12-25 mm. Thickness of the hacksaw blade in mechanical devices ranges from 0.63 to 1.25 mm.
But the electric type tools have the cutting inserts longer than 150 mm and not more than 55 mm in width. tool thickness 1,25-2,5 mm.
Sturdy material should be used for blades production. This is why steel is chosen. But its type can also vary:
HCS carbon steel products are used for working non-ferrous and softer metals. Such fabrics are not as strong as their other counterparts.
HSS high-speed steel blades are characterized by a high level of wear resistance of the teeth. However, such a tool will be expensive, and the plate itself with teeth turns out to be brittle.
Bimetal BIM type products. Hacksaw blade steel is carbon steel, but a strip of high-speed material is attached to the top to strengthen the tooth structure.
HM-alloyed steel. used for both metal working and for cutting concrete or bricks.
Tooth dimensions of hacksaw blades
Teeth size in this type of hacksaw is 2-2,5 mm. This characteristic must be taken into account when buying, paying attention to the marking.
International standards of classification use another type of marking, indicated as PPI or TPI. it is customary to define the number of teeth per 1 inch of the blade. For higher values of this parameter the blade is equipped with finer teeth.
According to the requirements of GOST, hacksaw blades are produced for cutting of different types. Depending on the ratio between the tooth pitch in mm and the number of teeth there are two possibilities:
- for single blades up to 265 mm in length, models 0.80/32, 1.00/24 and 1.25/20 are possible;
- sizes 1.40/18 and 1.60/16 are available for single and double blades up to a length of 315 mm.
How to attach the tool correctly
If the hand saw is equipped with a threaded mount, it is necessary to stretch the blade between the borders of the base plate and secure it to the holes with a wing nut.
The blade should be fastened so that the teeth are directed towards the edge opposite to the handle. In this case moving forward means removal of the metal layer, and moving backward, toward yourself, is idling. In the latter case it is not necessary to apply force.
When using an electric tool the process of changing the blade will be about the same:
- Turn the head of the holder in the counter-movement of the arrow until the slot comes out;
- Remove the blade from the tool;
- Insert the new accessory and press until you hear a click, indicating that the slot is fastened.
Peculiarities of plate selection
Before installing a new tooling tool, you must understand which blade to choose for the specific purpose of use.
- Blade must be in one piece, without defects, chips, rust traces;
- It is necessary to check the saw for elasticity. high-quality tooling after bending comes to the original state;
- the number of teeth determines the speed of work. if you need to saw the workpiece quickly, choose a plate with a large number of them;
- durable and long-lasting are hardened iron and bimetallic products;
- for specific parameters of a hacksaw you should choose the length of the product corresponding to the marking;
- High-quality tools can not cost too cheap, but you should not overpay for it.
For quality and efficient work when cutting metal, it is necessary to choose a strong and reliable hacksaw blade. It is necessary not only to choose it correctly, but also to observe the rules of operation and storage. And regular change of accessories will help you to keep the tool in working order for a long period of time.
Blade for a hacksaw for metal. How to choose and install? |
Hacksaw blades for metal is one of the most undurable elements in the whole range of consumables for tools. Of course, much depends on the technology of work with metal and the skill to use a hacksaw, but you must be able to make the right choice of blade first. Today, we will talk about the choice and types, and learn how to easily change hacksaw blades.
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, but the second 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 attachment holes 300±2 mm, with the total length of blade not more than 315 mm;
- Double, with the distance between the fixing holes 300±2 mm, with a total length of blade not more than 315 mm.
Thickness of single version is 0,63 mm, double version. 0,80 mm. The height with a single row of teeth is 12.5 mm and with a double row is 20 mm.
GOST also regulates the pitch of teeth 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 can also use the 1.40/18 and 1.60/16 hacksaw blades in addition to the above mentioned ones.
According to the grade of material used for the manufacture of hacksaw blades for metal, produced from tool steels:
Range of hacksaw blades of domestic production is limited by this fact, but in specialized trading networks so called diamond blades with surface spraying by titanium nitrides or other high-temperature metals are widely spread. Such blades can be easily distinguished by their color: usual steel blades are dark gray, and sprayed blades can have different coloring. from bright orange to blue (depending on manufacturer).
There are also blades with a so called tungsten-carbide spraying, but they are extremely sensitive to bending stresses despite their very high hardness. Therefore, when cutting metal, their durability is insignificant.
The high strength of metal saw blades is ensured by an appropriate heat treatment. Two zones with different hardness values are distinguished on the blade surface: directly by the teeth it makes from HS 6467 for alloy tool steels to HS 7378. for high-speed steels (for diamond blades this parameter reaches HS 8284), and in other zone. HS 4446. Considerable hardness difference confirms high sensitivity of the product to bending stresses, that is why the standard limits also the maximum force applied to the hand hacksaw. It must not exceed 60 kg with blades with tooth pitch less than 1.4 mm and 10 kg with blades with pitch over 1.4 mm.
Principles of blade selection
The durability of a cutter blade is also influenced by the quality of the coating. Chem coating is more common for domestic tools.Ox.Prm., Less common are tools with nitro enamel coatings like HC-25 or HC-132. it is necessary to remember that in case of long load, when the saw blade heats up, the enamel can crack.
While choosing high-quality hacksaw blades it is necessary to pay attention to the evenness of teeth setting: in high-quality products this parameter must not exceed 45 % of the pitch of the teeth at the length of 10 mm. Quality of the product can be estimated by the parameter of teeth evenness: difference in adjacent tops shouldn’t exceed 0,10 0,15 mm, which is checked with micrometer or depth gauge.
How to install the blade on the metal hacksaw?
mounting method is determined by the design of the mounting system on the hacksaw itself. In the case of threaded clamping the saw blade is put on the corresponding ledge, slightly tightened, and then fixed by means of the wing nut. With sudden changes in the load on the hacksaw, such a mount will have to be periodically checked. With hacksaws that have a lever-type device, the process of installation and replacement is simplified: simply pull out the lever, which is located on the side opposite to the handle of the hacksaw, put the blade on, and return the lever to its original position.
How to use a hacksaw
When properly tightened, the blade should make a slight ringing sound and vibrate slightly. When working, such a blade should not change its direction of travel under load.
For single sided blades it is important to correctly position the direction of the teeth. Their inclination should be directed from the handle. most users perform the main working movement away from yourself, which is when they make the metal cut. Reverse motion is intended only for returning the hacksaw to its original position. When trying to cut metal and during idling, the geometry of the teeth, not adapted to such loads, will tear the tooth from the base, and as a result, the blade may be destroyed. This phenomenon is especially common with diamond blades.
Recently so-called bimetal blades (designation. BIM) have become popular, when a strip of high-speed steel is welded on the main band of hardened constructional steel like steel 45. Quality makes all the difference: The metal grade of Chinese-made saw blades is often not guaranteed (and neither is the quality of the welding), which is why it is not uncommon for bimetal blades to delaminate when working with hard metal.