South Bend 9/10K METAL LATHE METRIC TRANSPOSING 37/47 COMPOUND NYLON GEAR This is a FDM made Nylon gear stack (compound gear) 0.625 Bore - install directly on to the stud - no bushing needed This gear made out of out of Nylon - tough and flexible plastic No lubrication required Only Nylons should be used for gears where a slippery surface is desired. All other materials (PLA, ABC, PET, etc.) will grind creating a plastic dust and eventually fail! For details, please review all pictures and compare to OEM gear shown Do not waste money for ABS, PLA plastic gear that may strip or melt The (47/37) gear is commonly used for transposing the feed rates on metal lathes for cutting metric sized threads. The 47/37 ratio is 1.27027 is very close to 1.27 with margin of error of only 0.0026" per foot. Gear depth .375 (3/8") 37t Gear depth .375 (3/8") 47t Stack Thickness .750 (3/4") Center bore .625 (5/8") Diametrical Pitch (DP) 18 Thanks for reading! Here is a feedback we've got for this Item: Perfect - exactly as described and an amazing deal! .?:**:?.10.?:**:?.STAR.?:**:?.EBAYER.?:**:?.PERFECT.?:**:?. THANK YOU!