Bahco Round Chainsaw Files are round files for sharpening the cutting teeth on saw chain, in eight diameters from 3.2 mm (1/8 in) to 6.3 mm (1/4 in).
Pick the file that matches your chain. Bahco lists the 3.2 and 3.5 mm files, 150 mm (6 in) long, for 1/4 in pitch chain. The rest are 200 mm (7-3/4 in) long: 4.0 mm for 3/8 in RG chain, 4.5 and 4.8 mm for .325 pitch, 5.2 mm for 3/8 in, 5.5 mm for 3/8 in and .404, and 6.3 mm for 1/2 in pitch. Your chain maker's file size is the one to go by. Each file comes in a skin pack that works as a sleeve to protect it in your kit. New to sharpening? Watch Pat's chainsaw sharpening video, then pick up the files you need.
Bahco traces back to 1886, when Johan Petter Johansson founded a mechanical workshop in Enköping, Sweden. He invented the modern pipe wrench in 1888 and patented the adjustable wrench in 1891. The Bahco name comes from B.A. Hjorth & Co., the firm that sold his tools, and the brand is now part of Snap-on.