The Crescent 6" Triangle Single Cut Slim Taper File - Carded, part 21866NNB. It has a single cut, for a smoother finish and draw filing. Supplier specification: FILE 6" SLIM TAPER SINGLE CUT W/O HANDLE.
A slim taper file is shaped specifically for sharpening saw teeth — the taper and the narrow section let it reach into the gullet between teeth without touching the ones either side. It is not a general-purpose file, and using it as one rounds the edges that do the work.
