How to sharpen a chainsaw chain

Recommendation points

• Why is it so important to sharpen the chain on time and correctly?
• What are the requirements for the quality of sharpening
• Disadvantages of popular methods
• What are sharpening machines and how to use them
• Why machine sharpening is the most rational method

The quality of the chain sharpening affects not only the cutting speed, but also the wear and durability of the engine. In this article, we will tell you about different ways to sharpen a chainsaw chain and explain how to use special sharpening machines for these purposes..

All gasoline and electric saw chains are identical in design and can be sharpened at home. The need to put the teeth in order is evidenced by the appearance of chopped and torn chips instead of thin twisted shavings. With the further use of a blunt chain, its condition only aggravates, up to absolute unsuitability.

Why is it so important to sharpen the chain on time and correctly?

Failure to return sharpness to the teeth in a timely manner will result in poor performance, excessive consumption of gasoline and chain oil. The most obvious drawback and at the same time a sign of dullness is the need to apply force when sawing, while a well-sharpened chain itself is cut into the wood under its own weight of the chainsaw. This sign can be misleading if hardwoods such as hornbeams or Karelian birch are cut with a chain that is not designed for this..

With the further use of a dull chain, the load on the engine and transmission units increases significantly, which reduces their service life. The chain itself is strongly stretched under increased load and may become unsuitable for sharpening due to deformed teeth. Their twisted shanks break the guide groove in the tire and also render it unusable..

Possibly sadder scenarios: Saw chain breaking under load is one of the most common and severe injuries when working with chain saws. Yes, most of them are equipped with a protective brake and damper, but such protection does not always work..

What are the requirements for the quality of sharpening

Actually, one round file is enough to sharpen the chain, 15–20 minutes of time and a certain amount of experience. The lack of the latter can be compensated for with special devices, but even in this case, it is necessary to understand some of the design features and the principle of operation of the saw chain.

All chain links are the same, they consist of a shank that holds the chain in the tire, and a crown – a visible part that directly performs the cutting function. The crown of the link consists of a cutting shackle and a claw-like depth stop. Each subsequent tooth is a mirror image of the previous one relative to the plane of the tire, so the setting of the teeth is ensured.

When sawing, the sharp edge of the tooth acts like an end plane, respectively, and the crown of the link has three main operating parameters:

1. The angle of the cutting edge determines the cutting force: sharper for soft rocks, and duller for hard.
2. The angle between the edge and the plane of the cut determines the length of the removed chips, the dependence on the hardness of the wood is the same.
3. The depth of cut depends on the difference between the height of the edge and the limiter, which must correspond not only to the hardness of the wood, but also to the structure of its fibers.

When sharpening the chain, it is best to restore its original parameters indicated on the package. And nevertheless, no one bothers you to sharpen the acacia chain at more obtuse angles in order to be able to work with birch firewood for a long time and productively..

Disadvantages of popular methods

Some craftsmen are actively promoting the method of sharpening the saw chain using angle grinders. This is not the best option, if only because one-handed grinders with a 120 mm disc (and others are completely inconvenient to use) have too high revolutions, which is why there is local overheating of the teeth and uneven tempering of steel. It is also difficult to control key angles with a grinder. So the angle grinder in inept hands can not only lead to incorrect sharpening, but also to damage the entire chain. In addition, this method is unnecessarily traumatic, and abrasive particles that inevitably fall between the links reduce their working resource.

Many manufacturers add round profile files to the chain saws for sharpening or fine-tuning chains. The diameter of the files is selected according to the size of the chain used: when laying in the groove of the crown, the plane of the cutting bracket is located almost tangentially to the circle, due to which a sharp bevel of the tooth is achieved. This leads to the main disadvantage of this method: the bevel of the blade turns out to be rounded instead of straight, so it quickly becomes blunt.

Compliance with the control angles when sharpening with a file is monitored exclusively visually. For this reason, sharpening kits have become very popular, which, in addition to the file, also include a template and a guide rail. On the surface of the latter, there are marks that are aligned with the plane of the tire to set the correct angle. These tools cannot be considered the main sharpening method, they are used on the road for quick finishing and restoration of the chain. Otherwise, use a special tool.

What are sharpening machines and how to use them

The highest quality processing is only possible with the use of sharpening machines. Sharpening is performed directly with a thin abrasive stone rotating at a relatively low speed. The saw chain is located in special guides, it is easy enough to scroll it and substitute the desired tooth for sharpening.

Sharpening machines have a rotary bed, with which the angle between the edge of the tooth and the plane of the cut is set, it can be adjusted in a wide range. The cutting body itself is inclined towards the bed, which is also adjustable to set the sharpening angle.

The chain is positioned for machining by means of a spring stopper, which rests against the end of an adjacent tooth. For more confident work, directly during sharpening, the chain is clamped between the two guides of the bed by simply turning the handle. When working on the machine, the teeth of each row are alternately processed – first the left, then the right.

As for the adjustment of the depth stops, the machine does not have any special devices for this. Measurement is carried out manually using a control ruler from the sharpening set, if necessary, processing can be performed directly on the machine.

Why machine sharpening is the most rational method

The main argument against sharpening machines is usually called their high cost. Here you need to figure it out: the price of a household machine is about 3 thousand rubles, about the same amount will cost 10-12 calls to the master for sharpening the chain, performed during its operation.

And even if the payback were not so fast, machine sharpening has too many benefits. Firstly, it is a clear control of the key parameters of sharpening, and for all teeth at once. Secondly, when sharpening in the machine, defects such as a rounded bevel or metal tempering are guaranteed not to appear, which means that the chain will have to be sharpened less often and it will last longer. Well, as an additional advantage of the machines can be called the convenience of their use, not only when sharpening the chain, but also during the sawing process.