uxcell 5/16-24 x 1/2 UNF 10.9 Alloy Steel Hex Socket Button Head Screws 20Pcs Product Name : Socket Button Head Screws;Material : Alloy Steel;Color : Black Tensile Strength : 10.9;Head Type : Socket Button Head;Thread Type : UNF Screw Size : 5/16-24 x 1/2";Thread Dia. : 5/16";Thread Length : 1/2" Head Diameter : 13.5mm/ 0.5";Head Height : 4.5mm;Hex KeySize : 5mm Weight : 135g;Package Content : 20xSocket Button HeadScrews