The chain you use for sawing will be made up of just a few components - but those components have a bearing on what the chain will be best suited to, and how safe it is.
Although there are many different types of chain, made for particular applications such as rip-cutting, cross-cutting, metal cutting, chains (for the moment at least) can be divided in to standard chains and safety chains.
A standard chain has the following components:
- Cutter: this, as the name may suggest, cuts the timber - but it also regulates how much timber is cut.
- Tie-Strap and Rivets: these hold the components together and the chain gets its flexibility from the use of rivets, in the same way a bicycle chain does.
- Drive Link: this performs several functions as it transfers drive from the engine, cleans the guide bar groove as the chain rotates and carries the oil to lubricate the chain and bar. This link must match the bar in use as several different sizes of chain are available.
The components above form a standard chain, but there is an additional chain component that can add to the safety of this item by smoothing out the cutting action, reducing vibration (and therefore whitefinger) and reducing the chance of kickback. This component is called a Guard Link and is really a modified drive link. This link has a sloping top, and it's position in front of and alongside the cutter helps the lift the wood up to the cutting edge.
Cutters come in a variety of profiles, which are best suited to particular applications and each has it's own advantage and disadvantage.
- The chisel profile is good for use in softwoods and it has a fast cutting action to slice through the timbers. This cutter profile is prone to dulling quickly and is therefore less durable than other types of cutter.
- At the other end of the extreme is the chipper profile, which is ideal for hardwoods, but has a slower cutting action. However, the advantage of this cutter is that it is more durable than the other types - and that potentially means less sharpening :-)
- In between these two types is the semi-chisel profile - this is a good all-rounder balancing the speed of cut of the chisel, with the durability of the chipper.
Next post... pitch and gauge.