Our 35BS10H sprocket is an ANSI standard sprocket with a 1/2" finished bore that has 2 setscrews and no keyway. This size sprocket is available with a keyway here. 35BS10 sprockets are a 10 tooth sprocket that works with ANSI #35 roller chain. These sprockets are manufactured from 1045CD carbon steel material. The sprocket teeth are hardened for increased wear resistance.