With over 35 different ranges of machine screws and micro screws in stainless steel, PTS are one of the largest distributors in Europe for both Metric to DIN specifications and American UNC / UNF threads to ANSI/ASME specifications. All are available to buy online now. A machine screw, also sometimes referred to as a machine bolt, is a screw that is typically designed to be fastened to a tapped hole with a corresponding nut to hold two object together, although there are a few types capable of tapping their own holes. These types of screws are, in general, not as large as socket screws or hexagons and are normally fully threaded as standard. They are categorised by the head shape and drive used in the head. The main head shapes are pan head screws (flat on top and rounded on the sides), countersunk (tapered on the underside of the head so they can lay flush with the object they're driven into) and raised countersunk (also known as an oval head which is a countersunk but also has a slightly rounded top). The main types of drive used with machine screws are slotted, pozi, phillips and torx. Torx screws were originally trademarked to Camcar Textron but many versions are now available with names such as hexalobular drive, t-drive, star drive and 6lobe. They are all 6 pointed drives designed to resist cam-out and to allow for a higher torque to be exerted than a similarly-sized conventional hex socket, slotted or phillips head. This reduces damage to the screw head or driver tool. Thumb screws and thumb nuts are designed to be turned easily with the thumb and finger rather than with tools to prevent over-tightening. Knurled thumb screws and nuts have a series of straight ridges rather than the more usual criss-cross pattern. This allows hands or fingers to get a better grip on the knurled object than would be provided by the originally smooth metal surface. Knurled fasteners are typically used in electrical components, musical instruments and automobiles. PTS have the largest range of American Threaded (UNC / UNF) machine screws in Europe, starting at just 0un diameter. If you can't see the fasteners you need online then please call us on +44 (0) 1342 410758 or email us at firstname.lastname@example.org.