Similar torque to thrust conversion can be achieved by rotating the axial set screw to drive the rotating retaining nut along the screw or by rotating the axial retaining nut to drive the rotating set screw through the nut. The hexagon head screw has a washer face and a chamfer point under the head, while the hexagon bolt has no washer face or chamfered thread. These fasteners are usually equipped with loose features such as nylon patches and particles, left-hand threads, or drill bits for wire locking. Threaded hole connections that do not allow the use of nuts may benefit from bolts, a full threaded hexagon bolt. From lightweight nylon and aluminum to silicon bronze, some materials are transformed into hexagonal bolts and capscrews with specifications for key, strength to weight ratio, corrosion resistance and ductility requirements. The thread used for fastening is machine thread. The machine thread has a 60 degree thread angle and is made of a continuous running spiral pattern. Ball screw pair It is mainly used for nuts or threaded holes. Plastic screws have a thread and are designed for soft materials. It is usually made up of a screw thread material with a high degree of rigidity and can not be pulled out of the screw by a high degree of force when the screw thread is made of other materials. It is used for wood, fiberglass and metal, also known as self tapping screws. There are two kinds of steel and stainless steel. Sleeve screw thread, mainly made of two materials, steel and stainless steel.