M20 Unbrako Socket Head Cap Screws ISO 4762 in Black Oxide High Tensile Steel Class 12.9

Also known as an allen screw or allen bolt, or simply a cap screw. Socket head cap screws are a modern machine threaded fastener, an alternative to the standard hexagon headed bolt. The geometry of the hex drive mechanism means that these internal contact surfaces are protected from external damage. A hex or allen key is therefore required to fit these fasteners. Conforming to ISO 4762 or DIN 912, UNBRAKO® socket head caps are manufactured to be stronger than other size for size high tensile versions. Please note that due to the nature of the surface finish on Unbrako products, some surface corrosion may be evident. This does not affect the performance of the product. Property class of 12.9.