This 35BS112 sprocket features a 3/4" finished bore including a key-way and two setscrews. It is a durable, high quality, and precision sprocket that fully meets ANSI Standards. This insures proper contact between the #35 roller chain and sprocket which prevents premature wear or breakage. Additionally it is also black oxide coated which increases resistance to the environment and will prevent early rust build up. We also offer stock bore sprockets, custom bore and made to order sprockets, and a full line of #35 roller chain. Fore more information, large quantities, or to get a custom sprocket please contact us and we will be happy to assist you.