How to use electric jigsaws
Electric jigsaws are widely used for sheet metal work. It will come in handy in the repair, carpentry or furniture workshop. With an electric jigsaw, you can cut soft and hard wood, plastic, drywall, as well as complex materials such as ceramic tile and metal. Depending on the hardness and brittleness of the material, as well as the type of cut you want to obtain, the technique of working with an electric jigsaw will have some peculiarities. In this article, we will talk about how to cut the most popular building materials.
The most common use of an electric jigsaw is for woodwork. Widespread use of this tool found in furniture production, where it is used to create elements and parts of different shapes.
If when working with an electric jigsaw, you can choose the right consumable and sawing mode:
- make straight and curved cuts;
- cut out circles without damaging the sheet metal;
- to cut thin metal;
- make products from wood with thickness up to 10 cm;
- cut plastic;
- sawing ceramic and porcelain tile.
Whether an electric tool can work with a particular material will depend on the power and type of tool (domestic, semi-professional, professional). Not all electric jigsaws have additional features, such as tilt cutting or the ability to connect additional elements and tools.
Cutting metal with a hacksaw
Cutting metal with a hacksaw
Hand hacksaw (saw) a tool designed for cutting thick sheets of strip, round and profiled metal, as well as for cutting slots, grooves, trimming and cutting out workpieces on the contour and other work. Manual hacksaw consists of a machine (frame) and a hacksaw blade. One end of the frame has a fixed head with a shank and handle, and the other end has a movable head with a tensioning screw and nut (wingnut) to tension the blade. The heads have slots into which the hacksaw blade is inserted and secured with pins.
Hacksaw frames are made either as a single piece (for single length hacksaw blades) (rare). or sliding, allowing attachment of hacksaw blades of different lengths.
To extend the hacksaw blade, the knees are bent until the rivet comes out of the cut, and shifted. The rivet is inserted into another notch, and the knees are straightened.
A machine with a movable holder consists of an angle piece with a handle by which the holder can be moved and clamped in position.
Hacksaw blade is a thin and narrow steel plate with two holes and with teeth on one of the ribs. Blades are made of such steel grades as U10A, R9, X6VF, their hardness HRC 61-64. Depending on their function, the hacksaw blades are divided into manual and machine blades. The blade is inserted into the frame with the teeth forward.
The size (length) of the hand hacksaw blade is determined by the distance between the centers of the pin holes. The most commonly used hacksaw blades for hand hacksaws have length L. 250. 300 mm, height b. 13 and 16 mm, thickness h. 0,65 and 0, 8 mm.
Every tooth of a hacksaw blade is shaped like a wedge (pick). On a tooth, as on a cutter, a differentiation is made between a posterior angle and a posterior angle. sharpening angle (3, the anterior angle y and the cutting angle 5. a p y = 90°; a p = 5.
The working conditions of the hacksaw blade are different from those of the cutter, so the angle values are different. When cutting metal of large widths, cuts of considerable length are obtained in which each tooth of the blade removes chips having the form of a comma. These chips must be placed in the chip space until the tip of the tooth comes out of the kerf. The size of the chip space depends on the value of the posterior angle a, the anterior angle and the pitch S of the tooth.
Depending on the hardness of the metal being cut, the forward angle of the teeth of the hacksaw blade can be zero, positive or negative.
Cutting performance of hacksaw blades with zero rake angle is less than blades with a rake angle greater than 0.
Blades with larger tooth angle are used for cutting harder materials and smaller ones for cutting soft materials. Blades with a larger angle of sharpening are more resistant to wear.
For cutting metals we mostly use hacksaw blades with the pitch of 1,3.1,6 mm which have 17-20 teeth on the length of 25 mm. The thicker the workpiece to be cut, the larger the teeth should be, and vice versa, the thinner the workpiece, the shallower the teeth of the hacksaw blade should be. For metals of different hardness blades with teeth number are used: soft metals. 16, medium hardened steel. 19, cast iron, tool steel. 22, hard, strip and angle steel. 22.
When cutting with a hand hacksaw, at least two to three teeth must be involved (cutting metal simultaneously). To avoid jamming of the hacksaw blade in the metal the teeth are set in one step.
The teeth of the hacksaw blade are set so that the width of the cut made by the hacksaw blade is slightly greater than the thickness of the blade. This prevents the blade from jamming in the cut and makes work much easier.
Depending on the pitch S the teeth are set on the blade and on the tooth.
Hacksaw blades with tooth pitch 0,8 mm (also possible for 1 mm pitch) must have teeth set on the blade (wavy), t. е. every two adjacent teeth bend in opposite directions by 0,25 to 0,6 mm. The setting is at a height no higher than double the height of the tooth. Set step is taken equal to 8S.
Blades with a tooth pitch of more than 0,8 mm are set on the tooth (corrugated setting). In this offset, if the tooth pitch is small, two or three teeth are set to the right and two or three to the left. In the middle step, one tooth to the left, the second tooth to the right, the third tooth is not taken away. At a coarse pitch move one tooth to the left and the second tooth to the right. The toothing is used for blades with a pitch of 1.25 and 1.6 mm.
Hacksaw blade setting must end at the distance of not more than 30 mm from the end face.
How to use a hacksaw
Preparing to work with a hacksaw. Before working with a hacksaw (hacksaw), the material to be cut must be firmly clamped in the vise. The level of the metal in the vise must correspond to the height of the worker. Then choose a hacksaw blade according to the hardness, shape and size of the metal to be cut.
Hacksaw blades with coarse tooth pitch are used for long cuts, and fine pitch for shorter cuts.
Place the hacksaw blade in the slots in the head so that the teeth are away from the handle, not toward the handle. In this case firstly the end of the blade is inserted into the fixed head and secured in position by a pin, then the second end of the blade is inserted into the slit of the sliding pin and secured by a pin. The band saw blade is tensioned manually without much effort (application of pliers, vises, etc. is forbidden).) by turning the wing nut. In this case, the hacksaw blade must be held away from the face for fear of bursting.
How to choose a blade for a hacksaw
The durability of the hacksaw blade is also influenced by the quality of the coating. For domestic tools the most widespread coating is Chem.Ox.Prrm., less common are tools with nitro enamel coatings of HC-25 or HC-132 type. Keep in mind that under prolonged loads, when the saw blade heats up, the enamel can give cracks.
When choosing a high-quality hacksaw blade you should pay attention to the evenness of tooth setting: in high-quality products this parameter must not exceed 45% of the pitch of the teeth on a length of 10 mm. Product quality can be estimated by the parameter of teeth evenness: the difference in adjacent tops should not exceed 0,10 0,15 mm, that can be checked with micrometer or depth gauge.
Sooner or later the band loses its quality and needs to be replaced, but it is not always cost-effective to install a new blade. Having a considerable service life in terms of strength characteristics, it is economically advantageous to give the tool for repair. The band saw machine is freed from the sawblade, which will be operable again after certain operations. The main task is to restore the cutting capacity of the blade. Determine the necessary procedures for this application:
- Welding. Used when the integrity of the product is compromised, some teeth are lost, or other serious damage is incurred. Welding takes into account the steel grade and location of the joint, with the same requirements as for industrial production.
- Cleaning. Work can pick up melted material particles, scale, and other foreign matter. This makes cutting very difficult and impairs the quality of the cut. Performance degradation does not have the best effect on primary production. After cleaning, the blade is ready to be installed in the band saw. This type of repair is often done on site.
- Sharpening. The cutting edge is repaired by machining with an abrasive tool. Tooth pitch and tooth shape should remain the same. Alteration of saw geometry will result in a change in blade performance.
- Setting. Required quality for free running of the belt in the material being worked. Under the stress of the working process, the deflection of the teeth from the blade that was set during production is reduced. The saw begins to bite or deviate from the direction of motion. Correct deburring will bring back the necessary performance.
All kinds of blades can be repaired, from simple woodblade models to bimetal band saws for hard steel. Tool reconditioning improves basic economics, making production more profitable.
How to choose a tool and blade
When choosing a saw, you should pay attention to the distance between the fasteners. You need to buy a tool that can accommodate interchangeable parts of different sizes. When buying a hacksaw blade for metal, consider the following parameters:
- Strength of material to be cut. If the saw will be used to cut soft sheets, a blade with minimum hardness made of X6VF steel is used. Professional metal saws are equipped with parts made of high-speed materials. Saw blades with diamond or tungsten inlay provide high quality of cut.
- The thickness of the sheet to be cut and the quality of the cuts. Selection criterion is the number of teeth acting per inch of material (PPI). For cutting thin sheet metal when you want a smooth edge, we recommend choosing parts with a PPI greater than 24. When cutting speed is more important than quality, the index should be less than 24. PPI increases as tooth pitch increases.
- Type of coating. Russian-made tools are coated with Chem.Ox.PPI. Less common are saws with enamel coating. Keep in mind that the enamel may crack over a long period of time. There are bimetal products when a strip of high-speed metal is overlaid on a steel band.
- Uniformity of tooth guidance. Spikes should not deviate from the axis by more than 45% of the tooth pitch.
STANLEY 0-20-108 Metal Hacksaw FatMax “5 in 1
In this review we are going to tell you about two-blade metal saws “5 in 1” from well known producer of wide range of hand tools and related products from STANLEY company. This hacksaw was purchased at ONLINE TRADE.RU.
The hacksaw comes in a cardboard package. On the front of the package there is the name of the manufacturer and the product line, the hacksaw model, the possible configuration of the hacksaw and the pattern of blade changes.
On the reverse side there is similar information supplemented with pictures of the hacksaw applications and information about the manufacturer. No other instructions are included with the hacksaw, but they are not needed, because the construction of the hacksaw is simple and intuitive. Both on the obverse and the reverse of the package two figures 150kg/330kg can be found, but we were not able to correlate them with the parameters of the hacksaw.
Hacksaw is made of high quality painted cast metal with reinforcing ribs, has an extremely rigid construction and does not sag even with high applied force. The handles are rubber coated, have an ergonomic shape, lie very well in the hand and do not cause discomfort even during prolonged work. This allows you to hold the hacksaw firmly and confidently in your hands, apply greater force to the sawed object, which makes it possible to saw even the most difficult materials.
The weight of the hacksaw is an impressive 1019 grams, length. 430 millimeters, maximum depth. 120 millimeters. Manufacturer’s stated blade tension strength of up to 100 kilograms.
Includes hacksaw, 300 mm (12 in.) bimetal metal blade (24 teeth per inch) and drywall blade.
The main advantage of the saw in question, besides the quality of workmanship and reliability, is the possibility of its transformation and use in five different variants.
Standard hacksaw for metal with 300 mm blade (blade strength up to 100 kg) This is how it was originally shipped. Used for standard material cutting.
To remove the blade pull back the cover at the bottom of the handle (arrow), open it, loosen the hinge-lever tensioner. The blade can be easily removed from its locking pins afterwards. Reverse order of blade installation.
Metal hacksaw for 45-degree sawing.
To transform into a 45-degree metal hacksaw, remove the blade and install it on the 45-degree locking pins. This option allows the saw to cut flush, along surfaces with minimal indentation.
Low Profile Metal Hacksaw
To transform into a low profile metal hacksaw you must remove the main blade, remove the front handle (by sliding it forward), and mount the blade on the locking pins. This variant can be used for sawing in cramped conditions, where it is inconvenient or impossible to use a full-size metal saw.
To transform into a mini hacksaw for metal, you must remove the main blade, remove the front handle (by sliding it forward), take out the blade for plasterboard from the blade storage compartment, insert the blade into the upper guide of the hacksaw and secure it with fixing screws. This option can be used for cutting in extremely limited conditions where a full-sized or low-profile metal saw cannot be used.
To transform into a drywall hacksaw, you need to remove the main blade, remove the front handle (sliding forward), take out the drywall blade from the blade storage compartment, the blade is fixed with a fixing screw in the removed front handle. This saw can be used to cut holes and cut various materials like drywall, etc.п.
In general, this tool can be recommended as a home masters, often using a hacksaw, as well as for professional use, because the quality of manufacture and characteristics of the hacksaw allow using it for large amounts of work.
Metal hacksaw blades. characteristics, types, and selection
Metal hacksaw continues to be popular among handheld cutting tools. The main advantage of this tool is that it can always be used when a power 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 properly. In this article, the master plumber will tell you the characteristics of the blade of a metal hacksaw.
The main feature of the blade for sawing metals are very small teeth, as large ones are impossible to work with metal.
In any model, domestic or professional, the teeth are made of hardened metal, as they must exceed the hardness of the metal alloy, for which the tool is used to cut. The size of the blade varies from 150 mm to 400 mm.
To consider hacksaw blades 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 appearance of the angle grinder (angle grinder), as well as circular, saber saws and jigsaws, hand saws have lost their popularity, but have not disappeared completely.
- For machine units. these include band saws that are used in industrial conditions (designed for machine tools). For band saws, blades with appropriate parameters are used: length, thickness, material of manufacture, sharpening and shape of teeth. In the home such units are used only when it is necessary to carry out high-precision cutting of metal parts. For such units a special band blade is used, the teeth of which have a coating of hard-alloy materials. In band saws not only tooling is used for cutting metal, but also for wood. Band saw blades need additional water cooling during the work that extends the life of the devices as well as reduces the load on the driving mechanisms of the machine units.
- Stand-alone electric units are tools that have supplanted handheld jigsaws. These include sabre saws and electric jigsaws. For sabre saws blades of corresponding shapes and technical parameters are available. For jigsaw blades for metal also have the appropriate parameters, so when choosing them, it is important to consider what type of tool consumables are designed for.
Hacksaw blades for metal are distinguished primarily by the material of manufacture:
- Carbon steel. they have low strength characteristics, so they can be used for cutting non-ferrous and soft metal. This class 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. Fast-cutting saw blades are labeled HSS and have a hardness rating of up to 73-78 HRC. There are high-speed steel blades with diamond coating that have hardness up to 82-84 HRC.
- Bimetallic. so named because of the use of two types of steel. They have created a furor on the market, quickly supplanting their analogues. Bimetal blades are based on materials such as carbon steel, onto which a strip of high-speed steel is welded. These are designated by the letters BIM. In terms of strength, they are the same as the fast-cutting ones, only due to the use of carbon steel as the base material, they have high strength and resistance to warping.
Universal mini. hacksaw for metal
Those who repair various home appliances, products, designs or make them with their own hands in the arsenal of a home workshop, there are many different tools, devices, and among them, of course, hand-held metal saw, simply. metal hacksaw. Industrial companies make hacksaw blades for such tools according to different technologies, from various carbon instrumental or high speed steels (and even from aluminum alloys). Some blades are completely hardened to high hardness while others only heat treat the teeth. But all blades are very fragile and often break, especially with careless work, in two, and sometimes even in three pieces. Over time, lots of pieces of different lengths with still sharp teeth (from almost new blades) are accumulated, and throwing them away as scrap metal. not in a businesslike way.
Some craftsmen suggest using at least a longer fragment of the blade: anneal the broken end, drill a hole here for the pin, and refine the frame of the industrial hacksaw itself under the fragment. This is labor-intensive, it can damage the tool and during annealing it shortens the already shortened working part of the band saw blade.
To use parts of broken blades, I made a small, you might say versatile mini. A metal saw, especially handy for making small parts.
The design of the tool is not complicated, although it requires welding work. Mini. The hacksaw can be made in the garage. Material, labor and financial costs are quite small, but the thing is very useful.
To make the machine you will need: steel bars with diameters of 8 and 12 mm; six M6x10 screws; two normal M14 nuts and a wooden handle (you can use from a file).
BASIC TECHNIQUES FOR MAKING PARTS
The nuts have to have a little bit of thread bored out to 13mm. I did it with a round file, and in one of the faces I threaded the MB.
Made the rack and frame-holder. To the holder I welded by electric arc welding a shank for the handle. I cleaned the seams with an “angle grinder”. I also used it to make a flattened edge on the frame-holder and slots for blade slices 1.5 mm wide at the ends of both parts.
I assembled the rack in the following sequence: put two nuts on the holder with the distance between them 12 mm (radial holes must be on the opposite side of the flattenings), tightened the screws and inserted the rack until it stops in the holder flattenings between the nuts
Insert the hacksaw blade into the slots in the rack and holder and tighten the screws. Clamp the blade this way. Screw in screws on one side until they are in light contact with the blade. Screw in screws with force on the other side. This method allows you not to destroy the fragile web at the points of the bolts, it will serve as a guide when welding the rack with the nuts. But first you need to align the rack correctly, if necessary to fix it with a clamp. I welded the stand to the nuts with an electric arc weld. Cleaned the weld seams with an “angle grinder”. To prevent cracking of the handle at the shank, it is necessary to drill in it an axial hole with diameter of 4 mm to a depth of 55 mm and reamed to a diameter of 8 mm to a depth of 20 mm. To give the hacksaw a marketable look, I painted it.
The design of the tool allows moving and fixing the stand on the frame-holder even at quite a close distance from the handle and using blade slices from 70 mm up to almost the whole blade length without any modifications. The attachment of the blade is quite handy and fast, making it possible to use even some machine blade scraps.
With such a hacksaw even long strips can be cut and deep cuts and slots can be made (for this purpose the hacksaw blade must go out of the grooves behind the ends of the stand and the holder down to the depth of the slit). In this position of the tool you have to work with it more carefully: you can press a little bit more than it’s supposed to or bend it a little. and the blade breaks. It is preferable to use a new blade fragment for this type of work as its teeth are sharp and the set has not worn out. I also use graphite and lard based grease to reduce friction. It holds on to the hacksaw blade for a long time. In the absence of one or the other component I lubricate the blade with machine oil, even used oil.
As you can see in Figure 1 the machine doesn’t have the traditional knurled nut tensioning screw. The method of tensioning the web is explained below.
In order to secure the webbing and for it to have the necessary tension, it is necessary to set the stand at a distance from the rear clamp to the length of the webbing fragment and secure the webbing in the slots of the stand and the holder. Then the rack with nuts by hand or by lightly striking the inner nut on the handle side with a hammer tilt forward on the holder until the tension. This method takes care of the play in the nut and holder. Tighten the screw on the nut on the side of the handle and follow. on the other nut. This method straightens the stand and tightens the blade. It is not necessary to extend the remainder of the blade up to 150 mm in length; it is sufficient to fix the stand on the holder and to secure part of the blade in the slots (stand and holder) as indicated above. The rigidity of the structure will prevent the blade from breaking.
The design of the machine allows the use of wider blades as long as they fit into the slot in thickness. For safety reasons sharp corners on broken blade ends should be rounded on an emery machine.
If at least one tooth on the blade breaks during work. Do not continue working, otherwise adjacent teeth would break and all others would be blunted quickly. To restore the cutting capacity of a blade with a chipped tooth, it is necessary to grind two or three adjacent teeth on an emery machine. Remove the broken tooth or its remnants that are stuck in the slot on the workpiece.
In order to use the sawblade breakage on a standard hacksaw with a fixing size of 300mm I suggest making extensions from “soft” steel of a thickness of one mm: one of 150 mm and two of 100 mm. The extensions allow for the use of single-hole web scraps no matter which part of the blade you use: the front or the back or a scrap without a hole. The dimensions 150 mm and 100 mm are approximate; they refer to the distance between the two 4.1 mm holes and the third 4.1 mm hole on the extension and blade cutter between the hole and the notches or between the notches, not the overall dimensions of the design.