Standard: ASME/ANSI B18.3-8; Screw length: 3 inch (includes the head part) Thread Size: 5/16"-18; Thread Pitch: 18 TPI Hex Drive Size: 3/16 inch; Package: 10 Pcs Head Diameter: 0.6 inch (min)- 0.66 inch (max) Material: 304 Stainless Steel 18-8 that you will probably see in your pans and cookery tools. It's used for a wide variety of home and commercial applications. Because of its slightly higher strength and wear resistance than type 316, it's also used for nuts, bolts, screws and other fasteners.