Arbor Spacer Low Carbon Steel Full Hard Temper Thickness 0.001 In Thickness 0.025 mm Thickness Tolerance +/-0.0001 In Inside Dia 2 In ID Tolerance +0.011 In Outside Dia 2 3/4 In OD Tolerance +/-0.002 In Keyway Width 1/2 In Keyway Depth 3/16 In Tensile Strength 80 000 PSI Rockwell Hardness B90 Meets AISI 1008-1010 Package 10