BBI Cap Screw, Fully Threaded, Measurement System: Imperial, 1/4-20 Thread, 3/8 in Length Under Head, 5 Grade, Medium Carbon Steel, Zinc CR+3, UNC Thread, 5/32 in H Head, Hex Head, 120000 psi Tensile Strength, Material Specification: ASTM B633, 25 to 34 HRC Hardness