T-Bolt, Medium Strength, Steel, Black Oxide Finish, Thread Size 3/8-16, Thread Type UNC, Length under Head 2 In, Thread Length 1-1/2 In, Head Height 1/4 In, Head Width 11/16 In, Slot Size (In) 3/8 In, Tensile Strength 4650 PSI, Rockwell Hardness C25-C34, Meets/Exceeds Grade 5 T-BoltsMedium carbon steel with black oxide finish.