(10 Sets) 1/4-20X2-1/2" Stainless Steel Hex Head Screws Bolts, Nuts, Flat Lock A Hexagon Bolt is a threaded fastener with a hexagonal head shape, and are designed to be installed using a spanner. Hexagon bolts are favoured for their robust shape, which makes them suitable for more heavy-duty fastening applications. Hexagon bolts are also generally available in larger sizes than alternative fasteners. As their name suggests, Full Thread Hexagon Bolts are fully threaded. This type of bolt is required when the shaft of a fastener is being inserted completely into a threaded hole. Fully Threaded Bolts are often used to securely fasten two threaded sections together. Made from 18-8 stainless steel, Fullerkreg? brand screws have good chemical resistance and may be mildly magnetic. Length is measured from under the head. Screws that meet ASME specifications comply with these dimensional standards.DIMENSIONS: Diameter: 1/4" | Length: 2-1/2" | Thread Type: 20 tpi Coarse Thread (Standard) Package includes ten each of bolts, hex nuts , Flat Lock washers