Socket Head Cap Screw Head Type Low Material Alloy Steel Black Oxide Finish Thread Size 18 Drive Type Hex Socket Drive Size 5/16 In. Thread Type Coarse Thread Style Fully Threaded Thread Direction Right Hand Length under Head 1/2 In. Thread Length 1/2 In. Head Height 5/16 In. Thread Dia 5/16 In. Head Dia 7/16 In. Temp Range - 50 Degrees F to 550 Degrees F Rockwell Hardness 33 to 39 Min Tensile Strength 150 000 psi Meets/Exceeds ASTM A574 Package Quantity 100