Socket head screws have a machine screw thread in imperial and metric, distinctive with their six sided hexagon recess in the head for driving with an allen key or hex driver tip. Socket head screws come in a range of head types and are for use in tapped housings, but can be used with nuts and washers. They are common in the construction of machinery and in the marine industry and are typically referred to as cap screws or socket screws.

For Australian customers see Stainless Steel Capscrews and Stainless Steel Grubscrews