Arbor Spacer Low Carbon Steel Full Hard Temper Thickness 0.093 In Thickness 2.362 mm Thickness Tolerance +/-0.0030 In Inside Dia 1/2 In ID Tolerance +0.011 In Outside Dia 3/4 In OD Tolerance +/-0.002 In Keyway Width 1/8 In Keyway Depth 3/64 In Tensile Strength 80 000 PSI Rockwell Hardness B84 Meets AISI 1008-1010 Package 10