How to Sharpen Circular Saws Correctly
Sharpening of circular saws should be carried out regularly to avoid damage to the building material. We will tell you how to sharpen a saw blade with and without soldering, what equipment and tools to use.
The disk tool for cutting wood is always useful during construction. The circulation saw is convenient in that it allows you to quickly cut the material with minimal effort and time. As for the quality of the cut, we can say that it is perfect, but only when the saw is working and well sharpened. Otherwise, even dangerous to work in such a tool, so you should spend sharpening the saw blade.
It is not difficult to determine the need for a sharpening operation: a blunt tool cuts a workpiece of poor quality, which immediately catches the eye. There are two options: either give the disk to the workshop, which is not always beneficial in terms of time and money, or sharpen the saw blade with your own hands. This may seem complicated at first glance. But if you delve deeper into the essence of the saw device, it will not be difficult to carry out tool maintenance at home.
When to sharpen a circular saw
There are absolutely certain signs by which you can judge the state of the instrument. Sharpening is necessary when the following is clearly evident:
- During operation, smoke occurs, the specific smell of burning wood, the casing covering the teeth of the saw begins to heat up quickly.
- When moving the tool along the workpiece, significant efforts must be applied, as if to push the saw forward.
- After cutting the material and visual inspection of the sawn edge, black soot or a lot of chips, fiber burrs, and chipped areas are visible.
- With a careful examination of the saw teeth in a magnifying glass, you can see that the cutting parts have not sharp, but rounded edges.
All this requires an immediate cessation of work, otherwise there is a high risk of material damage and wear of the circular saw to a state where sharpening will no longer help it.
The main angles of sharpening circular saws
The tooth of a circular saw, which is usually made of carbide metal, has a complex structure. He usually has three cutting edges, so you need to sharpen the teeth so as to sharpen these edges. But the main thing when sharpening is to observe the angles at which the tooth planes diverge from the edges, and the angles of attack between the tooth plane and the workpiece. The last point is important to maintain the characteristics of the saw blade.
The front face, the one that first cuts into the workpiece in the direction of movement of the saw, forms the main cutting edge with the rear face. The angle at which the front face meets the material is called the front angle Y (angle of attack). The angle between the rear face and the front is the point angle. If you take away the rake angle and the angle of sharpening from 90 degrees, you get a back corner.
In practice, it is important to observe when sharpening these angles for each type of disc. It is on the front corner of the saw that are divided into types:
- Longitudinally cutting, where the rake angle should not go beyond 15-25 degrees.
- Cross cutting, where it is permissible to sharpen the front face of the tooth at an angle of 5-10 degrees.
- Universal discs, which quite easily cope with both longitudinal and transverse cuts, their front angle should be maintained in the region of 15 degrees.
The bevel angle of the rear and front planes is also important: the sharper it is, the easier it is to enter the material, but wear is faster.
Follow the rules! When sawing hardwood, sharpening of saws must be carried out so that the point angle and bevel angle are as small as possible (within acceptable limits). This increases the life of the disc until the next sharpening.
Types of wiring of teeth of a circular saw
Before sharpening the circulation saw, you need to check whether there is a tooth alignment. To do this, measure the width of the tooth with a caliper, and then make a small cut in the hardwood blank and measure its width. If the circulation disk is divorced, then the cut should be wider than the tooth. Otherwise, the saw teeth must be bred before sharpening operations.
The complexity of the wiring process is due to the need to take the teeth to the side at the same distance. This can be achieved by using a factory-made tool for distributing circulating saws. Each tooth should be started to breed from the middle of its size. For wood materials of different densities, the degree of tooth setting should be different, but without going into details, it can be said that for sawing soft species, they are bred wider than for hard ones.
There are three main ways of wiring:
- Stripping type wiring. This method boils down to the fact that after two the tooth remains in its place without change, the rest are rejected in different directions. Such a saw preparation is good for working with solid wood.
- A variant of the classic wiring, when alternately the saw teeth are diverted to the right and to the left. This universal method can be applied to almost all types of saws.
- The so-called wavy layout, the distinguishing feature of which is the removal of the teeth not at a strictly defined distance from the center, but at different distances with a deviation of 0.3–0.7 millimeters.
General rules for sharpening a circular saw
To sharpen the disks for the circular saw, you must not allow them to wear out severely, namely, the radius of rounding of the cutter should not be more than 0.2 mm. The following basic rules are followed:
- First of all, the main faces are exposed to processing, of which the front one wears out more.
- In extreme cases, with strong wear of the side faces, they are corrected.
- No more than 0.15 millimeters of metal thickness is removed at a time.
- When fine-tuning the edges with an electric tool, overheating of the metal is not allowed, in which case its properties deteriorate.
- To ensure the maximum life of the saw, when it can be sharpened up to 30 times, both sides should be sharpened: front and back, removing the same amount of metal.
- Sharpening of circular saws with non-intended tools is not allowed, for example, an angle grinder and a disc for cutting metal.
After carrying out the main sharpening operations, you can modify the teeth with a fine sandpaper. Quality Control tool grinding occurs under the operating conditions. If everything is in order, the cutting of the material will be clean, smooth, without visible defects and blackening.
How to sharpen a circular saw
Sharpening discs is not possible without the use of a special tool. For these purposes, you can use:
- Special circles for sharpening saws, made on the basis of diamond abrasives.
- The usual file for sharpening the saw, but you also need to have a vice to secure the saw and a wooden block used as a guide.
- Processing on professional equipment is the fastest and highest quality sharpening method, but requiring large material costs for the acquisition of a tool.
Do-it-yourself sharpening at home
Attention! To sharpen the circular saws with your own hands, it is desirable to have certain skills in sharpening the tool. If there are none, at least practice emery while sharpening a regular knife.
When working with the disc, the main thing is not to spoil the cutting surface, and this can easily happen if the hand trembles, the feed angle is violated. In order to avoid negative consequences, you should study sharpening methods, and then everything will turn out right. There are a manual method for restoring cutting elements of a circular saw and a method using grinding equipment.
Independently sharpen the teeth manually with a file so that it is of high quality, it is possible if they do not have a bevel, that is, the surface of the front face is perpendicular to the surface of the canvas. The process looks like this:
- From dense wood, a bar is cut with a cross section of about 50×50 mm and a length of 100 mm. The sides of the bar should be located strictly perpendicular to each other.
- Mark with a marker any tooth that will be reporting and the first to be processed.
- The saw blade is clamped in a vice with the beam in such a way that the front face of the workpiece is flush and in the same plane with the surface of the beam (the beam in this case acts as a guide for the file).
- A thin file (its thickness should allow it to fit freely into the cavity between adjacent teeth) is applied to the surface of the tooth being machined, and at the same time sharpening is carried out to the bar and methodically moves back and forth.
- So gradually grind each tooth, monitoring the condition of the beam and while developing its surface, shifting a little plane.
Use of machines
With the help of a special machine, circular saws are sharpened very easily and quickly. The main thing. There is no need to monitor the angle of the disc. Having set it once, the operator only has to move the teeth into the processing area and make light clamps of the tooth plane to the rotating diamond disk.
On such equipment it is possible to sharpen carbide tipped saw blades and conventional circular saw blades. The simplest machine for tool-grinding operations of circulation saws has the following structural elements:
- An electric drive with a mounting system for a grinding wheel is a stationary part of the equipment.
- The stand, which moves along the guides, is its task to feed the saw blade into the processing area.
- The clamp of the saw blade on the stand, which is designed to hold the blade in the same position when it feeds to the grinding wheel.
Pay special attention! Disks with different types of teeth require an individual approach to sharpening. When the front face is slanted, its supply to the processing area is performed at an angle to the horizontal, for which one edge of the stand is respectively raised.
If you have additional questions on the topic of sharpening saws or you have your own experience in carrying out such operations, respond in the comments! Your comments are important to us!