Bar guage

[Stubby]

2 hours ago, htb said:

Yes they are the same width with the difference being in the drive link widths as you said. But the overall cut width are different as this made up of the right and left cutters swept area which overlap, the degree of overlap depends on the drive link width.

Therefore a .50 chain overall width is less than a .58 which is lee than a .63, which is why in theory a .50 chain cuts quicker than a .63 one and why a part worn chain cuts quicker than a new one as the overall cut width reduces as you sharpen the chain ( as cutters are not parallel to the guide bar they narrow slightly away from the cutting edge and drop slightly which is why you lower the depth guages).

Yep I always prefer a chain with about 3 sharpenings left in it . 

[Dan Maynard]

We have indeed been down this route. There are two types of 0.050 chain, the standard (Oregon type 20) which makes a similar kerf to 0.058, and a narrow one Oregon call MicroLight (type 95). This has narrower cutters, runs on a different bar, and cuts a narrower kerf than standard 050 to reduce power demand.

 

The new Stihl 0.050 chain is narrow kerf, like type 95, so the cutters are smaller. Hence it cuts 20% faster.