'21' on the chain question...

Sophomoric question.. I purchased a cheap-o unbranded saw with a 24" bar that has ended up being awesome. Paid like $110 4 years ago and danged if it has been underpowered but cuts like a champ. Came with 2 24" chains.

I am trying to determine what file size I need to sharpen the chains. The cutters have a '21' on them. Can anyone tell me what they are, what file diameter I need to get? I might just get a pferd sharpener, but not sure what to get.

Have used this saw to grind thru some silver maple rounds over the years and was amazed at how sharp the chains remained. Not used heavily, but it does the job. For the record, I have among other things some Stihls that are my go-tos. Still, I never thought this off brand thing would work very long but it keeps humming. Takes a little longer to get thru a large round, but hey. My standard wood is pinon and lodgepole pine which the Stihls eat for breakfast.

tx

 

Figure out the pitch and that will determine what file you need.
The chart on the right shows "#21" , I'm guessing it is a 3/8 pitch chain based on that = 3/16 file if that's the case.

 

Most of the 3/8th pitch that I’m aware of is 7/32, unless you have some low-pro. Is there a pic or brand name on said chain?

 

Its either 3/16 or 7/32. Bring the chain to an OPE dealer and see which size fits the curve of the cutter. They usually sell loose files.

 

There is also 13/64" files, between 3/16 and 7/32"
I think a lot of chains and dealers recommend 13/64" for 3/8" pitch chain, and the 2 in one Stihl sharpener has 13/64" round files in it, I believe, for 3/8" x 50 chain. And .325 has 5/32" round files in it. Personally, I go to 3/16" on .325 chain and 7/32 on 3/8" chain. On the first sharpening you will end up opening up the hooks/gullet a little bit more. It' easy to see this on the chain, by just laying a file on the tooth of a brand new chain.

 

I have Stihl kits for the PMM chains like on the MS170 , .325 and 3/8.
Now I am curious and will have to look later when I get home as to what they actually are.

 

Same here. I buy files by the dozen. Now with the little saws i need 5/32.
I guess CAD has its drawbacks!

 

3/8 lo pro = 5/32
.325 = 3/16
3/8 stihl = 13/64 (but most use 7/32)
3/8 Oregon and .404 = 7/32

 

I believe the 21 is an Oregon .325 .058 ga chain

 

would that be the same as Stihl picco 3/8"P chain?

 

What file is needed for the standard chain that comes on a ms170?

 

I believe its 5/32" which is what i used on mine.

 

Thanks buZZsaw BRAD

 

YW sir

 

Yes

 

Are you aware of anyone making a file smaller than 5/32 for the Stihl 1/4” chain?

 

My circa 1973 020 rear handle came with a file guide with an 1/8" file. File was dull as hell and i used the 5/32 to sharpen the chain. Its some weird chain size too.

 

I also want 1/4” Stihl chain that doesn’t have double drags/rakers/depth gauge/guides

 

Yep, that's one reason I switched out my .325 chain and bar for a 3/8 x .050 on my 261. The .325 may actually be the better choice for that saw, but I wanted to stay with 3/8 pitch chain.