9" , 10" 11" Lathe 72 tooth Nylon gear This fine Nylon gear has improved design for better durability and performance compare to OEM and superior to other replacements Made out of Nylon - tough and flexible plastic Nylon naturally slippery, no lubrication required! Runs quieter and smoother Only Nylons should be used for gears where a slippery surface is desired. All other materials (PLA, ABS, PET, etc.) will grind creating a plastic dust and eventually fail! For details, please review all pictures DP: 16 72 tooth gear O.D. : 4.625" Gear face width: 7/16" 0.4375" Center bore: 5/8" (0.625") with 5/32" key Do not waste your money on ABS or PLA plastic gear that may strip or even melt! Introductory price - please share installed images and review.