Parameters of circular saw blades
A circular saw blade is a metal circle with teeth at the end. Wood circular saw blades are designed for different tasks, which is something to consider when buying. The wrong tooling will result in an uneven cut, it will run tight with expected consumable damage.
When cutting, be sure to watch out for overheating. Steel is characterized by an increase in body temperature with constant friction, especially against wood. This process expands the metal, which leads to a “figure-of-eight” warping. Deformation begins to show itself in a small runout that has not been experienced before. Often an increase in temperature causes small bumps on the body of the metal, which are not visible to the eye, but can be felt. Over time they begin to expand and become even more noticeable. Operating a circular saw with this disc will lead to motor wear and breakdowns in the armature.
You must take into account the probable expansion when buying since even a disk that matches the tool’s specifications can begin to expand at temperatures. There are thermocompensators to eliminate this defect. These are the slots that take up the expansion and do not let it get deformed. It is also a safety feature that you have to take periodic breaks to allow the motor and the wheel to cool down.
The cleanliness of the cut is indicated by the number of teeth. The performance models have fewer teeth and larger sizes. They are also positively sloped. They are much faster at cutting through board or wood, but the edges are covered with debris and uncut fibers. You have to clean them yourself with a chisel.
Wood saw blade for a clean cut has a larger number of teeth (from 42) with a negative slope. their productivity is reduced, but in exchange they give a clean edge without protruding fibers.
It is important to look at what the saw blade is for. The circular saw has a tooling for:
They have different shapes of cutting edge, which changes their purpose.
So that readers do not get lost in the maze of the modern circular saws market, we have prepared 5 basic criteria that will help to decide on the choice. Consider them in order of importance.
The outside, or outer diameter of the disc must not exceed the dimensions of the circular saw guard, otherwise it will not fit in the seating. An increase in the parameter leads to an increase in the depth of cut. Diameter ranges from 65 mm to 500 mm.
Seating, or inside diameter. hole size in the center of the tool. Determines if the saw blade can be mounted on the spindle. The most popular sizes: 16, 20, 22, 30 and 32 mm. But the full range is much wider, from 11 to 50 mm.
Producers can install pins in the saw’s seating for additional fixation. In that case you need to choose a saw blade with the appropriate holes.
Number of teeth
As the number of teeth increases, machining speed decreases, but cutting fineness improves. And vice versa: the fewer blades, the faster the work, but the cut becomes less accurate. The characteristic has its own classification, presented in the table:
|№||Name||Number of teeth, pcs|
Tooth sharpening tilt
Grinding inclination. angle of deflection of cutting edge of tooth from the radius of saw blade. The picture clearly shows how this characteristic can influence the operation. The angles are as follows:
Standard: 5 to 15°. Universal sharpening. Suitable for all types of cuts.
Positive: 15-20°. Ideal for longitudinal cuts due to the grip effect.
Negative: down to.5°. Suitable for cross-cutting, does not splinter.
Standard setting is 3.2 mm. The thinner the disc, the hotter it gets and the quicker it fails. Thickness guarantees long tool life, but slows down the work. In this case there is an overrun of material due to the wide kerf.
RECOMMENDED CUTTING CONDITIONS FOR BAND SAW EQUIPMENT
|Workpiece material||Material designation||Cutting speed, m/min||Cooling|
|Structural steels||St 35-St 42||St 35-55||40-55||60-80||1:10||Х|
|St 50-St 70||30-45||50-70||1:20||Х|
|21 NiCrMo 2||30-45||45-55||1:10||X|
|Nitriding steels||34 CrAI 6||20-35||1:20||Х|
|34 CrAI Ni 7||20-35||1:20||Х|
|Chrome steels||C 35-C 45||35-55||55-75||1:20||X|
|42 CrMo 4||40 XM||30-40||35-50||1:20||Х|
|36 NiCr 6||40 CRH||30-40||50-60||1:20||X|
|Bearing steels||100 Cr 6||25-35||50-65||1:30||X|
|105 Cr4||X 15||25-35||50-65||1:30||Х|
|100 CrMo 6||20-30||40-50||1:30||Х|
|Spring steels||65Si7||65 Г||30-40||-100||1:30||Х|
|50 CrV 4||50CFA||30-40||40-60||1:30||Х|
|High carbon tool steels||C80W1||U8A||25-35||40-55||1:30||X|
|C 105 W 2||U10A||25-35||40-50||1:30||X|
|Alloyed||105 Cr 5||30-40||50-60||1:30||X|
|x 40 CrMoV 51||4CR5MOFS||20-30||30-40||1:30||X|
|x 165 CrMoV 12||XM12||20-35||1:30||Х|
|56 NiCrMoV 7||5CRNIW||25-3||20-40||1:30||Х|
|100 CrMo 5||20-30||35-45||1:30||Х|
|x 32 CrMoV 33||20-30||30-45||1:20|
|High speed steels||S 6-5-2||Р6М5||25-40||1:30||X|
|Valve steels||x 45 CrSi 93||30-40||1:20||Х|
|High-temperature steels||CrNi 2520||25-40||1:10||X|
|x 20 CrMoV 211||25-40||1:10||Х|
|Heat-resistant steels||x 10 CrAI 7||20-30||1:10||X|
|x 10 CrSi 6||20-30||1:10||X|
|Stainless and oxide steels||x 5 CrNi 189||25-35||1:10||Х|
|x 10 Cr 13||12Х13||25-35|
Choice of the ideal wood saw blades. Find out about our tips for circular saws.
It is not enough to buy a reliable circular saw. Without a good harness it can’t do the job. Only high-quality circular saw blades can let you achieve high performance in woodwork.
Scope of application and main features
Small and medium in depth of cut circular saws belong to the class of manual equipment, which has sufficient maneuverability, convenience. At the same time these saws have low power, so they are not known for high output. Saws with great depth of cut are more professional equipment, that’s why they are used in small companies and woodworking workshops.
The second most important factor is the power of the machine inside the saw structure. Exactly for this reason parameter depends on the performance of the product. In the 3rd place of the main characteristics is the disc rotation speed. Sawing solid materials should be done with tools that have higher index.
How to choose circular saw blades
There are many tasks that a circular saw can handle. But, unfortunately, for the whole Spectra works can not be satisfied with one saw blade. It is necessary to take into account a number of factors in order to choose the required part correctly and to achieve the task set for it. From size, to number of teeth, to material. Incorrect choice can lead to tool breakage and sometimes to an accident.
When choosing pay attention to the technical characteristics of the circular saw, and only on the basis of this you need to choose a suitable wheel. Some increase the load on the motor and may not be suitable for your tool.
Much depends on the type of your circular saw. see manual. But there is also a dependence on the type of work. what material will be processed.
Cutting metal with a Circular Saw: Toolsday with Metal Saws
- Outer Diameter. Selected by the size of the guard.
- Inner Diameter. Depends on the size of the power shaft of the circular saw.
- Number of teeth. A larger number of teeth has a negative effect on cutting speed and motor load, but the quality and cleanliness of the cut is improved.
- Tooth pitch. Circular saw blades are most commonly positively angled, making them ideal for making longitudinal cuts.
- Circle thickness and bit thickness. Determines how thick the kerf will be. Greater widths increase durability, but increase the load on the motor.
Saw blade marking
High-quality products generally have laser markings. Marking information gives blade thickness, outside and inside diameter, number of turns, number of teeth.
For example, a blade with values of 190 x 1.8 x 20 mm means the disc has an outside diameter of 190 mm, thickness of the bit 1.8 mm and a disc thickness of 20 mm. Burr thickness is a key factor when selecting a blade. Moderate thickness will not overload the gearbox, which will ensure longevity of the tool. Such disc would be good for cutting 40 mm boards.
The material for these discs is high-speed steel, sometimes chrome vanadium steel. This steel is alloyed with molybdenum, tungsten, vanadium, chrome that significantly increases strength properties. Label. CV or HSS.
Circle saw carbide
High-speed steel is strong enough, but for some types of work it is not enough. Then you use hard-carbide materials marked TC. The blade is half chrome vanadium steel and the teeth are tungsten carbide and are brazed on.
Diamond circular saw
Cutting stone, concrete and other hard materials requires diamond-tipped discs that are laser-welded. One of the toughest types of discs that enables working with high-density materials.
Watch DIABLO Blades Cut Through My Steel Like Butter, “CRAZY FAST”
How to choose the right circular saw for metal
Metal circular saws are common in industry and everyday life. on a domestic level, the metal saw. is a hand saw with interchangeable blades. That’s the tool we’ll see at the first lines of any search engine.
The industry is characterized by more productive models: the most important equipment of this category at the moment is a band saw for metal, although 20 years ago the most common type of saw for metal in the workshops was a mechanical hacksaw. There are still some machines like this and, even more surprisingly, they are even available new! A mechanical hacksaw is an obsolete and noisy machine, usually with a non-swiveling vise. Interchangeable tool for it. hacksaw blade. Uneven wear and tear. more in the center, the edges are not touched and are therefore less economical than disc or bandsaw blades.
expensive, but also much more productive machine was and still is a metal circular saw. Its older variant is the segment saw, also called Heller saw.
Nowadays, both self-fed and hand-fed circular saws use high-speed steel blades. These blades have a comparatively higher number of teeth, as do blades with carbide teeth. High-speed steel saw blades, not to be confused with wood saw blades, are most often used to cut galvanized metal ducts. This is due to the large number of teeth and therefore the space between them, called the tooth pitch. This factor allows very thin steel to be cut without undercutting.
For productive cutting of steel circle or aluminum slabs, it is best to use an automatic disk cut-off machine. This machine is equipped with saw blades with hard-alloy teeth. The disc rotates at high speed and is cooled by the oil mist. Well, if steel beams or pipes have to be cut, then the number one in all industries. is a band saw. Bandsaw. Economical and quiet equipment for cutting both thin and thick walled workpieces.
As for our promise of advice on selecting a circular saw for metal, the types of tools listed above are not really relevant. We specialize in relatively light and simple hand-fed saws and cut-off machines with a carbide-tipped saw blade that runs without additional cooling. We just want to be objective and give as complete a picture as possible of the state of metal sawing in the present and the not too distant past.
Cutting Steel with Circular Saws | Metal Cutting vs. Standard Sidewinder
Chapter 2. Circular saws for dry cutting metal. Purpose
Circular saws are a convenient and relatively inexpensive way to cut steel workpieces in shops and directly on sites. Several companies in the world specialize in their manufacture and design of some models are very similar. This is mostly the case with handheld circular saws and pendulum cut-off saws.
Manual circular saws for metal are designed for cutting of steel sheet up to 12 mm thick, as well as profiled sheet and sandwich panels up to 80-100 mm thick. As the name implies, circular saws of this type are held in the hands while working. Their design, sometimes allows the disc to be tilted at an angle of up to 45 degrees to the plane of the support pad, and this gives great versatility. It is even possible to chamfer welding in one movement when cutting sheet metal.
Unfortunately, the lightness and speed with which circular saws cut thick steel when compared to a conventional angle grinder, for example, is offset by the relatively high cost of the saw blades. However, the only alternatives are sheet metal shears or laser cutting, which can in no way compare to hand saws neither in price nor in mobility.
So, handheld circular saws will allow you to cut quite efficiently and accurately:
- mild or low-alloyed sheet steel up to 12 mm
- lentil sheet
- lattice decking
- Profiled sheet metal with a wave height up to 84 mm
- sandwich panels.
Slightly less efficient, but still possible to cut with these saws:
- steel pipes and profiles. it is hard to see where the cut will go, so if accuracy and repeatability are important, it is better to use pendulum saws
- Scrap metal, like old railroad cars, car bodies, or farm equipment. structures can shift during cutting and the disc can get jammed. This can lead to breakage. In these situations, where accuracy is not important, use gas cutting. However, be aware of the risk of explosion.
- stainless steel. this is because stainless steel does not conduct heat well. This causes all the extra heat to rush through the disc and cause it to warp and deteriorate. It is better to use something with liquid cooling.
Pendulum cutting machines are very good for cutting long products: pipes, profiles or circles. The name pendulum saws comes from the form of motion in an arc around the swing axis. These saws are more suited to the classification. Small or portable machine for metal cutting. The maximum diameter of circular saws available for this type of machine, at the time of writing, was 400 mm. However, the most common so far is a 355 mm or 14″ blade. Cutting machines with a disc of this diameter can cut blanks with a cross-section of up to 130 mm. In some cases, it is acceptable to cut a rectangle of 95×180 mm.
What is best entrusted to a pendulum circular saw with a carbide blade:
- Steel or cast iron pipes
- Rolled steel, in particular angles, channels or I-beams
- cable tray with wall thickness of 1.5 mm and higher
- profile pipes or a closed profile of a more complex cross-section
Slightly less effective but still possible to cut with such machines:
- open thin-walled profile with a wall thickness of less than 1 mm. vibration, you need to use inserts to prevent the vise from squashing. Helps but reduces performance
- cable without armor and steel core. Any steel element in the cable is hardened, or made of spring steel. That’s a real hassle. That’s why we advise to cut the cable with care.
- steel disc. the saw blade will fail very quickly in any metal with thickness over 6 mm, but we have experience in cutting 50 mm and more. The multi-purpose Rage discs are particularly suitable for this purpose.
- stainless steel. Pipes made of AISI 302, 303 or 304 can be cut, but only if you allow enough time for the saw blade to cool down between cuts. Thus, cutting becomes unproductive or wasteful.
- carbon steel. The discs don’t handle carbon steel very well. Mark 30 and higher require care and slowness. The life of the blade will also be reduced.
And at the end of the review we can not ignore the multi-purpose mitre saws Evolution Rage. Many people are interested in these saws’ ability to cut steel profiles, pipes and other workpieces. Based on our experience we can say that it is possible. But no more than. And here’s the thing.
Crosscut saws with a broach can cut quite wide workpieces. They are very good for accurately sawing boards at different angles. The clamping of the workpiece is done at some distance from the mowing line so that the rotary table is not blocked. And the clamp is a lightweight clamp. All this is fine for cutting wooden boards and even aluminum boards used in car trailer production, but not the same for cutting steel profiles. Vibration in the long arm of the puller causes damage to the carbide tines. Another factor. It was not until 2020 that the discs installed on mitre saws began to match the speed of the saw, before that the speed of the disc was too high. That’s why we don’t have to talk about continuous cutting of steel profiles or pipes on a crosscut saw. If steel needs to be cut occasionally, such equipment is quite suitable. If, however, the task is to constantly work with rolled steel. our recommendation is either a cut-off saw or a handheld circular saw for metal.
All power wood handsaws have in common that the metal cutting teeth are used to cut through the fibers of the wood. This principle also applies to hand and petrol saws. The difference stands in how the working organs of electric saws are arranged, how the teeth are fixed and what shape they have.
Electric circular saw blades, hacksaw blades or scroll saws have a wedge or trapezoidal shape, may be flat or have a compound shape and one or more cutting edges.
By design, work tools can be:
- With a circular working body;
- In the form of a single- or double-sided saw blade;
- As a saw chain mounted on a special rail.
Circular saws usually have triangular, wedge or trapezoidal teeth with complex shapes. On the working surface, one or two cutting edges with teeth sharpening are applied. The principle of this power saw is to cut the wood fibers as the blade rotates around its center. The teeth alternately gnaw into the wood, removing some of the fibers with the cutting edge of the tooth.
Sabre saws use a reciprocating motion of the tool. Depending on the saw settings, the movement can be 3 cm or 5 mm. To work with a saber saw, you select saws that differ in their purpose and use:
- For working with wood:
- For sawing plastic and chipboard;
- Used for aluminum or thin sheet metal.
Chain saws consist of a closed flat chain with intricately shaped teeth, which is driven by a chain drive gear from the saw’s motor. Saw chain moves endlessly on guide bar. the cut is performed by the teeth on the right and left sides of the chain. For this kind
chains are not selected according to the direction in which the wood fibers are sawn, but according to the strength of the wood.
There are several varieties of electric wood saws for home use. They all vary in motor power and performance, size, and operating principle. But when selecting a power saw, it is recommended to talk about a specific type of tool, which has certain properties and has a certain design, this is the simplest and most straightforward classification of power tools. Today there are five main types of saws, which are widely available on the market and oriented to both professional and domestic use:
The handheld circular saw blade parameters include outside diameter, inside diameter, thickness, number of teeth, tooth inclination, and tooth configuration.
Outer diameter varies from 13 to 25 cm. This characteristic has no effect on the material processing speed, but it determines the depth of cut. The inside diameter, otherwise known as the fit diameter, is an important parameter that corresponds to the size of the power shaft on the circular saw.
Circular wheel thickness is usually measured in tenths of a millimeter. 3.2 mm is considered standard. This parameter determines the kerf width.
The number of teeth affects the speed of cutting and the cleanliness of the material. The more teeth, the less time it takes to cut. However, the place where the cut will look less attractive. The number of teeth on a circular saw blade typically ranges from 10 to over 100.
Based on this indicator, all existing saw blades can be sorted into three basic categories:
- discs with fewer teeth: 10 to 40.
- discs with 40 to 80 teeth. They are of a universal variety: suitable for working different materials, both hard and soft.
- Circular saw blades with more than 80 teeth.