Grinding Wheel Thickness for Sharpening

[eweingarden]

I have an Oregon 410-120 chain sharpener which I use for chains on a Stihl MS 250. I recently bought a second chain saw (Stihl MS 311). The chains for the saws have different specs with respect to pitch and gauge. The Oregon Sharpener manual indicates using a 3/16" stone for some chains, and a 1/8" stone for other chains. I would prefer not having to change the stone each time I'm sharpening the chains from the different saws. In addition, the Oregon manual indicates using a different thickness stone for different model chains, even though the chains have the same specs. I'm not a professional; I use my saws for harvesting wood to turn on a lathe. With all that said, I'm confused about whether or not I can use the same stone for the different chains. TIA for any and all feedback.

 

[Bob Hedgecutter]

Yes, generally speaking- 3/8 LP and .325 chain use the thinner stone and standard 3/8 or .404 use the next size up.
The reasoning being, the larger stone would cut into the side plates of the smaller chain and the smaller stone on the larger chain would not cut the correct profile gullet.
Not that I have tried it- but perhaps with some clever angle setting, or multiple pass cutting- you perhaps could get a correct profile on the larger chains with the smaller wheel.
Maybe its just easier to have a few chains for the 311 and wait until all need to visit the grinder- swap wheels and do the lot in one sitting.
Another solution is a second grinder- one set up with the smaller wheel, other for the larger wheel.
But, then you need to buy a third grinder for the 6mm wheel- set up to do depth gauges.

 

[eweingarden]

Bob - thanks for your reply and info. I think I'll go the route of sharpening all of the smaller chains at one time, and then changing the wheel for the larger ones. Another question I have is: all of my chains are full chisel except for a semi chisel which I recently bought. I haven't used it yet, but when it's time to sharpen it, is there anything different I need to do because of the semi chisel profile? It's a 3/8 pitch; would I still use the 3/16 stone on this chain? Thanks.

 

[Bob Hedgecutter]

Full or semi chisel makes no difference- use the stone that matches the pitch and the angles you decide upon.
Different stones for different pitches is just the same as different file sizes for different pitches in hand filing applications- there are no file specifications for full versus semi chisel.

 

[eweingarden]

You've made this somewhat confusing topic (at least for me) clear. Thanks for your replies.

 

[Bob Hedgecutter]

You've made this somewhat confusing topic (at least for me) clear. Thanks for your replies.

It is only confusing until you know what you didn't know.

I am pretty sure the people that write the leaflets that claim to be instruction manuals for grinders all went to University and got degrees- not written by practical blue collar folk.