Types of discs and teeth, as well as the peculiarities of their restoration
The teeth of the disc are made of a specialized alloy of tungsten and cobalt (this is evidenced by the marking on the “front” side of the disc).BK, BK6, etc.).
Important! The longevity of a blade does not only depend on the alloy, but also on the quantity and correctness of the work performed.
The tooth has the following geometric planes:
At the intersection of geometric planes there are two working (cutting) edges:
- Straight. They are used to cut through sheet wood lengthwise.
- Trapezoidal. This shape provides a long sharpening time when working with wood of different hardnesses.
- Beveled. The main or auxiliary edge has an angled bevel that enables the disc to cut not only into homogeneous wood but also into laminated chipboard, fibreboard. In addition, the “beveled tooth” can cut plastic.
- Beveled. Universal form that allows you to make longitudinal and transverse cuts. This mold has one disadvantage, which is a rapid loss of sharpness of the working edge.
After the setting has been performed, the hacksaw must be checked for uniformity in height of teeth. Since the force may have been applied to it unevenly, there is a chance of teeth with less wear, which will protrude over the rest.
To identify such teeth on a hacksaw, you can use a simple method. It requires thick paper or cardboard along the length of the cutting blade. To sharpen a sheet of paper put on a flat surface, like a table, level it well and then press the cutting part of the blade hard against it. Teeth that are knocked out of alignment will make deeper dents in the surface.
This allows them to be easily detected and corrected before sharpening. To remove excess height, various scrapers are used. While doing this work, you should strive to maintain the shape of each tooth of the hacksaw as much as possible.
Why and when to sharpen?
Skilled professionals know the following signs that indicate that the saw is about to fail:
- When cutting wood, the hacksaw begins to sound different;
- it becomes visually noticeable that the tips of the teeth are rounded, lost sharpness;
- The color of the teeth will change;
- The sawing effort increases;
- the direction of the saw is poorly maintained;
- the teeth jam frequently in the wood.
Tooth setting must necessarily precede the process of sharpening the teeth. Tooth deflection from the plane of the hacksaw to the left and right must be achieved at a defined angle. A tooth deflection angle that is too small will cause the teeth to “sink” into the wood. Conversely too large an angle makes the kerf too wide, increases the amount of waste and requires too much muscle energy to pull the hacksaw. The purpose of sharpening the teeth is to restore the next tooth geometry:
Important! Hardened teeth cannot be sharpened. They are black with a bluish hue.
Features of sharpening longitudinal hacksaws
Also a fine-toothed diamond file is used here. The saw blade must be held vertically. How to properly sharpen a wood hacksaw for slitting? Two different sharpening angles can be used:
- The straight way. The tool is guided horizontally in relation to the hacksaw blade and removes a slight layer of material from the surface. Tooth backs and fronts are ground. The cutting edges are sharper as a result.
- Beveling. This technique differs from the first approach in the direction of the file relative to the hacksaw blade. Sharpening angle should be set at a slight bevel of about 75-80.
Sharpening file for chain saw chains. Sharpening tools.
A properly sharpened chainsaw chain is one of the keys to successful and productive cutting. A well sharpened chain puts less strain on the saw blade, overcomes the natural resistance of the wood and requires less lubrication, and lasts longer.
You can sharpen the chain by giving it to the sharpening point (it is usually at key-cutting shops or specialized stores). Alternatively, you can sharpen your saw chain yourself with some sharpening skills and knowledge.
There are two ways to sharpen a chainsaw chain yourself:
About sharpening machines for chains I have already written: Machine for sharpening chains: do I need and how to choose? Today we will talk about files for chains.
Sharpening file for chain saw chain. How to find the right one
When actively working on cutting dead wood or expanding the area of the homestead plot in the home workshop necessarily have a chainsaw. Even a chain saw of a trusted brand (e.g. STIHL) chain saw chainwheels occasionally wear out and therefore needs to be sharpened properly. In the absence of special devices with this problem will help to cope correctly selected file for chain sharpening chainsaw.
Possible ways and methods of sharpening the chain
Working with a file
The best solution. the simple machines for sharpening. This kit includes a round and flat file, special jigs, a caliper template, a chip removal hook, etc. Structurally, these aids may be different, but they share a common logic.
The diameter of the round file depends directly on the size of the chain:
- – Chains with ø 1,3. require a ø 4 mm file (used much more often);
- – Chains with a ø of 1.6 require a ø 5.2 mm file;
- – To sharpen the depth stop, use a flat file.
- With the chain brake on beforehand, clamp the chain saw bar firmly in a vise (a firmly clamped saw is the key to successful sharpening)
- Position the template so that the arrow is pointing toward the nose of the bar. Be sure to mark (maybe with chalk) the tooth where you started sharpening, otherwise you may go a second round;
- Grind in the direction indicated by the arrows. Remember, each chain tooth has a special factory notch. It indicates the maximum sharpening angle.
- In addition to the cutting tooth, there are limiters on each link. Sharpen them as needed. It is often necessary to do this if the height of the tooth is reduced as a result of sharpening and the chainsaw has problems working. As a rule, the limiter is sharpened after 2-3 sharpening teeth;
How to sharpen a small chainsaw. (What file to use).
If there are no skills in sharpening, it is better to start with inexpensive chains.
- The file should not go over the top of the cutting edge by more than 1/5 of the working part of the file. The pressure is carried out with the same force;
- The movement of the sharpening tool is made in one direction from yourself, and the number of movements for each tooth must be equal;
- To sharpen the vertical plane, the file position must be at right angles;
- For sharpening the horizontal plane, position the file at an angle of 20-30°
- If there are teeth of different heights, the benchmark is the smallest one.
Advantages: Possibility to charge the saw in the field. And it’s cheap.
Disadvantages: Takes time and effort. This quickly kills the file. Speaking of files: it is better to pay a little more and get a quality product. than to buy for 40-50 and throw it away after the first sharpening (tested in practice). Also, if the chain has ploughed the ground so well that its cutting edge has changed its original shape, it is difficult and not fast at all to sharpen it with a file.
Sharpening with an angle grinder
Professionals consider this work to be primitive. There is a risk of damaging the bar, and not only that.
The process (easy in appearance, but in fact. difficult)
- The chain also remains on the bar;
- We fix on the angle grinder a cutting disk on metal in thickness of 1,5-2 mm. It is desirable to take not new, that is, with a ground edge;
- Place an obstacle in front of the chain and bar (a chip will do);
- Sharpening at the right angle;
- When the work is done, the chain should be tightened properly.
With a professional approach and a trained hand, the number of sharpenings in this case can be more than 7.
A beginner, it is better not to experiment with the saw, the chain and the. with your body parts!
Advantages of the method: Fast, cheap and does not take away from the effort;
Disadvantages: You need special skills, a steady hand and the ability to obey the safety.
Electric sharpening machines
They have special setting functions to help position the chain at a certain angle. In doing so, it is possible to accurately and neatly bring the blade to the teeth of the chain. There are machines equipped with automatic vices. They are activated by bringing the disc closer to the edge to be sharpened. Convenience and functionality are of course high. You can find models at affordable prices.
Manually operated machines
The design of such a machine is similar to a bow saw. Only, where the saw blade is located, there is a round file. With this machine one can grind and dress the teeth by adjusting the proportionality of the top edges to the smallest (reference) size. Mechanism allows precise parameter setting. After adjustment to a reference tooth, sharpening is carried out in two to three movements. And then the transition. to the next tooth.
How To Sharpen A Crosscut Hand Saw
When it is necessary to grind a limiter, change a round file for a flat one.
Advantages of the method: Allows high-quality, convenient and without great physical effort to sharpen the teeth, including those that have lost their original shape.
Disadvantages: The price of the tool and the distance to the possible site of the saw.
After you finish sharpening, blow the chain with compressed air (from a compressor or pump) and put it in clean motor oil for a while. Of course, almost no one does such measures, but for the chain, it will only benefit.
Which one you choose for sharpening is up to you. This has to do with how often you work with your chainsaw. From the care with which you handle it. The quality of the purchased chain. And, of course, the ability to spend an enriched amount of money. It is impossible to compare methods, because as a German proverb says, apples should be compared with apples.
For those who did not know, we inform: hand saws are divided into three types. Some of them are designed to cut wood crosswise, others to work lengthwise, and there are universal saws that can cope with both tasks. It is the universal ones that are most common. And to determine the type of the saw is quite simple: the tool for cross-cutting sawing the teeth have a regular shape, for longitudinal. a strong bevel to one side, universal saws have one edge at a right angle and the other. beveled. A cross-cutting cut is made in both directions, i.e. the saw blade moves back and forth; for a longitudinal cut, the saw blade moves in one direction only. Accordingly, these details must be taken into account when sharpening the teeth.
External signs of a blunted cutting edge in a chainsaw tooth
Let’s remember that chainsaw tooth has a complicated configuration (see “Working angle” on page 66). Fig. 1), which also depends on the direction of movement of the chain. It has two working edges: the side one is perpendicular to the chain drive axis, and the top one is at a certain angle to the chain drive direction. In addition, each tooth has a limiter that determines the height of cuttings to be removed. Since the main cutting effort falls precisely on the working angle, then the whole subsequent work with the tool will depend on what angle to sharpen the tooth.
Figure 1. Chain saw tooth functional parts and how they look
Which File to use when sharpening saws?
Before you start working with a chainsaw for a long time, it should be inspected and a test saw should be performed, as a result of which:
- Visually inspect for the presence (or absence) of a tapered area adjacent to the corner of the tooth and a radius rounding on it. the main signs of blunting (see Pic. Figure. 2).
- Check the feed force at which the tool works steadily, with a fast production of the cut. For sharp teeth, the initial moment of tooth penetration into the wood is rapid, and without significant resistance to the material.
- Check if the chain vibrates when making a steady cut and if you can feel it, you need to sharpen the cutter.
- Inspect the appearance of the end face that has just been cut (especially if the tool is used for slit sawing). If there are rough chips and dents the chain should be sharpened.