Chainsaw Repair

Got my 2 loops today.  So which file to use on these?  3/16 4.8mm or find 5mm  or 13/64 5.2mm

Nice find!
 It would be nice if Stihl would re-introduce this sawchain. The Stihl factory recommended file size for the Topic Super 3/8 chain was 11/64" [4.5mm], but good luck finding that file size. Go with a common 3/16" file which is what Oregon 76LG spec calls for. I myself and other loggers in our area used 5mm files for these two chains, 13/64 is too big.
Us loggers had a habit of breaking smaller diameter files with our hand strength ha ha, so the suppliers gave us 5mm. Full size 3/8 we used 7/32 and 13/64.