When cutting various wooden materials (whetstones, logs, boards, slats, etc.), home craftsmen and professionals use circular and miter saws (hand or stationary). Without the use of such devices it is difficult to imagine the construction of a country house, as well as the manufacture of wooden furniture or the construction of a fence. The cutting elements of any wood processing device (electric or gasoline) are saw blades. A wide selection of these products is now available to the modern user (both in price and in the variety of manufacturers, sizes and purpose).
Varieties of wood saw blades
All discs for cutting wood are divided into two main categories:
- Monolithic, which are made from a continuous sheet of special tool steel. Due to the fact that the sharpening of saw blades made by this technology has to be done quite often, they are in the least demand among users.
- With carbide taps on the cutting edge of the teeth, with which you can achieve high cleanliness of the cut, and they also contribute to the durability of the discs. It is this category of cutting nozzles that has gained the most popularity recently (both among professionals and amateurs).
In production, saw blades are made in two ways:
- stamping (the product is cut out of sheet metal using templates);
- laser cutting method, which allows you to most accurately comply with all given geometric dimensions.
On a note! The manufacturing method affects both the price of the disk (stamped, of course, cheaper), and its quality and durability (laser in this regard, beyond any competition).
Specifications
The main technical characteristics of saw blades for wood for circular and miter saws (hand or stationary) are:
- outer diameter - from 65 to 500 mm (this indicator cannot exceed the dimensions of the protective casing of the device);
- the number of cutting teeth - from 12 to 100 pieces (the more teeth, the higher the load on the tool and the lower the processing speed, but the higher the cleanliness of the cut, and vice versa);
- the diameter of the landing hole is from 15 to 32 mm (depends on the size of the spindle of the circular saw, although some models of discs are equipped with special washers that allow them to be used with various devices);
- web thickness - from 1.5 to 3.2 mm (the higher this indicator, the stronger the device and, as a result, the longer its service life);
- maximum operating revolutions at which the manufacturer guarantees trouble-free long-term operation of the product - from 4000 to 16000 revolutions per minute.
Structural anti-deformation features
In the process of cutting, the surface of the disk is heated and, as a result, the temperature expansion of the metal. This can lead to deformation of the cutting device, a decrease in cut quality, or even to mechanical destruction. To prevent these negative phenomena, special technological compensation slots (of a straight or curved shape) are arranged on the outer side of the disk circumference. Their number depends on the diameter of the nozzle and is usually from 2 to 6-8 pcs. Naturally, the larger the disk, the more slots are needed to effectively compensate for its thermal expansion.
How it works: as the temperature rises, the metal expands, as a result of this, the size of the seam decreases, that is, the so-called temperature compensation occurs. Therefore, the disk does not change its geometrical dimensions even during long-term operation. In addition, these technological improvements reduce vibration and noise.
As additional tricks to extend the “life” of the discs and improve their anti-deformation performance, manufacturers use their know-how:
- recesses of a specific form applied to the surface using a laser;
- a circular groove located approximately in the middle of the diameter and equipped with a rolling method.
Grinding the surface of the disc and subsequent careful balancing greatly improves the vibrational characteristics of the wood sawing devices and reduces the load on the circular saw drive motor.
Leading manufacturers
The most famous manufacturers of saw blades for metal, wood and other building materials today are:
- German - Bosch, Metabo, Hammer, Stayer, Leitz and Einhell;
- Japanese - Makita and Ryobi;
- Italian - CMT, Freud and Felisatti;
- Russian - Interskol, Practice, Attack, Whirlwind and Encore;
- Belarusian - "Bison" and "BelMash";
- American - DeWalt and Jet;
- British - Saxton;
- Polish - Yato
- Canadian - FIT;
- South Korean - Keos.
Marking of cutting tools
Almost all manufacturers apply the basic technical information not only to the packaging, but also to the surface of the disc itself. Standard labeling contains:
- outer and landing diameters;
- permissible maximum rotation speed when using;
- number of cutting teeth;
- cut the thickness.
To facilitate the grinding process, the most important companies (for example, Makita and DeWalt) also indicate the angle of inclination of the teeth.
On cheap discs, the marking is applied with paint and, after a short use, is almost completely erased. Very inconvenient for the user. On expensive products, all the necessary information is applied by laser engraving, which remains on the surface of the product throughout its entire life.
The shape of the teeth of the cutting edge
The teeth on the disks intended for sawing wood can have a different geometric shape: straight, trapezoidal, beveled (alternately to the right or to the left) or triangular. The international classification of this indicator is quite complicated, and developers test this parameter in special production laboratories. The choice of one or another configuration of the shape of the cutting tooth of the disk depends both on the physical properties of the material being cut and on the planned processing speed.
Scope depending on the angle of inclination and the number of teeth
These two technological features mainly affect the cleanliness of the cut and the scope of the circular saw blades.
For longitudinal processing of wood, products with a small number of teeth (up to 55-60) and a positive angle of inclination of the cutting edge (when the teeth are tilted in the direction of rotation of the disk) are used. Moreover, the more (“more aggressive”) the slope and the smaller the number of teeth, the greater the speed cut and the “coarser” the cleanliness of the cut.
Loved by professionals (according to numerous reviews), a Makita Premium wood saw blade (carbide) with an outer diameter of 185 mm, a 30 mm bore, 40 teeth and a tilt of the cutting edges plus 18 degrees costs today about 2500 rubles. For those who use a hand-held circular saw from case to case, the Russian Whirlwind for 350-450 rubles, similar in size (diameter 190 mm, 48 teeth), is quite suitable.
For transverse cutting, a zero or negative angle of inclination and a large number (up to 80-100) of cutting teeth are used. This configuration slightly reduces the processing speed, but leaves a flat surface after cutting.
A high-quality 300-millimeter miter saw blade for Bosch Optiline Wood with 96 teeth and a zero angle of inclination costs about 4800 rubles. Naturally, such a device is economically justified to acquire for daily use. Those who have a woodworking machine, but do not use it too often, it is better to purchase a cheaper and universal device. A saw blade on a tree for a clean cut of the same size (with 100 teeth and an angle of attack of minus 5 degrees) "Bison Expert" (Belarus) will cost 2,400 rubles.
Naturally, the price of a disk (of the same purpose and manufacturer) directly depends on its geometric dimensions. The larger the diameter of the cutting device, the more expensive it is and vice versa.
Special or multi-purpose drives
Highly specialized saw blades for metal can not be used in wood processing. However, in the production of some installation or construction works, quite often there is a need for cutting a wide variety of materials (metal profile, aluminum corners, polymeric materials, wood of various hardness). So that the user does not have to spend a lot of time constantly changing discs for various purposes, many manufacturers have developed special multi-purpose discs (Multi Material or Multi Cut).
A saw blade for aluminum, plastic, laminate, hardwood Metabo Multi Cut with an external diameter of 254 mm, a hole 30 mm and 80 teeth costs about 5000 rubles. According to user reviews, such a cutting nozzle can easily cope with both transverse and longitudinal cuts of various types of wood, as well as particleboard and MDF (including laminated).
Bosch Multi Material for a similar purpose (with a diameter of 160 mm and 42 teeth) can now be purchased for 1800 rubles.
To dismantle temporary wooden structures (for example, foundation formwork or scaffolding), in the arrangement of which nails, screws or self-tapping screws were used, disks with a special shape of cutting teeth are used. The negative angle of attack (which is usually minus 5 degrees) and the specific geometric shape of the sharpening allows these discs to easily cope with both metal hardware and the remains of cement mortar. What makes them indispensable assistants at any construction site. It is for such purposes that the 216-mm carbide saw blade DeWalt DT1953QZ Construction (with 40 teeth of a special shape) is designed, which now costs about 900 rubles.
Discs for grinders
Angle grinder (more familiar to all of us as a grinder) is a universal tool that is available in the household of almost any home master. Initially, this multifunctional tool was not designed for sawing wood. Numerous attempts to adapt circular saw blades for use with angle grinders have rarely led to a positive result.
Now many manufacturers produce special saw blades for wood for grinders. Outwardly, they are largely reminiscent of circular analogues. However, such devices have a number of technological features:
- Tungsten carbide is used as a carbide material for soldering on the cutting edge of the teeth, which allows the use of such nozzles at high speeds (11000-13000 rpm).
- The diameter of the mounting hole strictly corresponds to the standard dimensions of the angle grinder spindle (22.2 mm).
- The outer diameter is 110-125 mm, which allows you to safely use such circles with a protective cover on.
Saw blades for the grinder, as a rule, are unified nozzles and are designed for processing wood (wood of various hardnesses), drywall, laminated particleboard, fiberboard and so on.
Universal product Status HSS 72T with an outer diameter of 110 mm, a bore of 22.2 mm, 72 teeth and designed for safe operation at 13000 rpm. Today it costs 550-600 rubles.
The original design of the cutting blade for cutting wood with a grinder is offered by Graff, Leman and Speedwood. A technological feature is the presence on the cutting edge of the disk of only 3-4 tungsten carbide teeth. According to the developers, such a device successfully copes with both longitudinal and transverse sawing of wood of various hardness, as well as laminate, parquet board, plywood and drywall.
A 125-millimeter wood drive for angle grinders (with a bore hole of 22.2 mm) Graff Speedcutter with three cutting teeth and a cut thickness of 3.8 mm costs about 800 rubles. The maximum rotation speed is 12,200 rpm, which allows it to be used with almost all models of grinders.
Chain sawing wheels on wood (from Verto, FIT, Lancelot or Squire), according to user reviews, have three significant drawbacks:
- high cost (for example, 2700-2800 rubles for a 125-mm Verto);
- difficulties with subsequent sharpening the chain;
- a fairly wide cut (6.6-7 mm).
What to look for when choosing
When choosing cutting devices for wood processing, it is necessary to pay attention to several key points:
- The type and characteristics of the tool (spindle diameter, casing dimensions and revolutions of rotation) on which you plan to use a carbide saw blade. For example, if the nozzle is designed to be used at a maximum rotation speed of 6000 rpm, it cannot be used at rates in excess of this value. And although many modern saws have a speed controller, it is important to first set the value indicated by the manufacturer and only then turn on the device.
- Direction of cut (longitudinal or transverse), as well as hardness of wood. The quantity, shape and angle of inclination of the cutting teeth depends on this.
- The thickness of the workpieces (boards, bars and so on). For example, if you select a disc with a diameter that is too small, you can not cut a thick part in one pass.
Finally
Although the saw blade belongs to the category of so-called consumables, each user wants him to last as long as possible. Therefore, buying a product from a time-tested and well-established manufacturer, you can be sure of both the quality of the device and its durability. The main thing is to choose the correct cutting nozzle and operate it only in the recommended modes.