Used for installing hexagon headed fasteners with a power tool. Also known as a nut setter. Shank Dia. inch: 1/4 Socket Size inch: N/A Socket Size mm: N/A Drive End Square: N/A Length mm: 65 To Fit: 5/16" fastener Shank Type: Hex Finish: Self Colour Material: S2 Hardened Carbon Steel Timco Magnetic Socket Driver Bit - Hex (Size 5/16 x 65 - 1 Each) in Silver