'Shoulder Screw, Alloy Steel, Plain Finish, Head Style Knurled, System of Measurement Inch, Thread Size 1/2-13, Hex Socket Drive Type, Drive Size 5/16 In., Shoulder Dia. 5/8 In., Shoulder Length 4-1/4 In., Thread Length 3/4 In., Head Dia. 7/8 In., Head Height 3/8 In., Screw Head Height 0.365 to 0.375, Shoulder Length Tolerance +/-0.005 In., Screw Head Dia. 0.853 to 0.875, Min. Tensile Strength (PSI) 140000, Shear Strength (PSI) 84000, Class 3A, Rockwell Hardness 32 to 43 HRC'