Arbor Spacer Low Carbon Steel Full Hard Temper Thickness 0.125 In Thickness 3.175 mm Thickness Tolerance +/-0.0030 In Inside Dia 7/8 In ID Tolerance +0.011 In Outside Dia 1 3/8 In OD Tolerance +/-0.002 In Keyway Width 3/16 In Keyway Depth 5/64 In Tensile Strength 80 000 PSI Rockwell Hardness B84 Meets AISI 1008-1010 Package 10