Standard Retaining Ring, External, Carbon Steel, Finish Black Phosphate, For Shaft Dia. 40 mm, For Bore Dia. -, Free I.D. 36.5 mm, Thickness 1.75 mm, Thickness Tolerance -0.060mm, Radial Wall -, Prongs -, Height -, Fits Groove Dia. 37.5 mm, Groove Dia. Tolerance -0.25mm, Fits Groove Width 1.85 mm, Fits Groove Depth 1.25 mm, Clearance Dia. (Compressed) -, Clearance Dia. Free O.D. -, Hole Dia. 2.5 mm, Tensile Strength (PSI) 150,000 psi, Rockwell Hardness RC47-54, Meets/Exceeds DIN471