04A (ASA 25) sprockets

04A (ASA 25) sprockets work with the smallest American chain, 1/4" (6.35 mm) pitch to ANSI B29.1. They are a good choice where forces are small and limited space and low drive weight matter.

04A (ASA 25) sprockets - a compact, light and smooth-running drive

The small pitch allows you to build a compact, light, smooth-running drive - it works well in small conveyors, light garden and agricultural equipment, electric vehicles and inch-dimensioned machines. We make the sprockets from C45 steel, and the smallest driving sprocket is also available with hardened teeth, which wear more slowly.

04A-1 simplex sprockets: hub and plate type

04A-1 (25-1) simplex sprockets in two versions: with hub - smaller driving sprockets mounted directly on the shaft, and plate - larger driven sprockets for welding or bolting to a flange.

04A sprocket vs 04 and 04B chain - frequently asked questions about ASA 25 sprockets

Does a 04A sprocket fit 04 or 04B chain?

No. The European 04 and 04B chains have a 6 mm pitch, while 04A has 6.35 mm. The difference is small, but enough to stop the rollers seating in the tooth gaps.