Mounting Holes: 47mm center-to-center Max Collar Diameter: 38mm All slot hole for high precision punch a punching processing,perfect fit for your 57mm Nema 23 Stepper Motor. The motor mount made of 5 mm steel integrated manufacturing process and welding on both sides to strengthen fixed reinforcement to ensure enough strength The motor mount made of 5 mm steel integrated manufacturing process and welding on both sides to strengthen fixed reinforcement to ensure enough strength. Alloy Steel Mount Nema 23 (57 Series) Stepping Motor Mount Installation 2-Phase 57 Series Closed Loop NEMA 23 Linear Integrate Stepper Motor With Encoder Nema 23 Plate NEMA 23 Mounting Bracket NEMA 23 Motor Bracket NEMA23 Stepper Motor L-Shape Mounting Bracket With Screws | Electrics Electric Motors Alloy Steel Mounting Bracket Durable alloy steel provide strong bearing pressure when printing. Silver Mounting Bracket For Nema23 Stepper Motor MB27 – Star International All slot hole for high precision punch a punching processing,perfect fit for your 57mm Nema 23 Stepper Motor Package Included: 3 X Nema 23 Stepper Motor Mounting Bracket w/ M4 Screws