[Self Tapping Screws Set]: 1Set - 500pcs x Hex Washer Head Self Tapping Screws, 1pcs x Hex Bit Socket. Thread Size: #12x1-1/2"(ST5.5x38); Hex Head Size: 8mm x 5.4mm/ 0.31" x 0.21"(Hex Width T); Flange Dia.: 10.5mm/ 0.41"; Hex Bit Socket: 8mm x 65mm/ 0.31" x 2.56"(Dia. ).