T-Bolt, High Strength, 4140 Steel, Black Oxide Finish, Thread Size 1/2-13, Thread Type UNC, Length under Head 2 In, Thread Length 1-1/2 In, Head Height 5/16 In, Head Width 7/8 In, Slot Size (In) 1/2 In, Tensile Strength 9933 PSI, Rockwell Hardness C32-C36, Meets/Exceeds Grade 5