Schraube – threaded fasteners

This category of standardized fasteners combines two types of shaft parts – bolts and screws.

One end is threaded, while the other has a head designed to transmit torque.

The connection is formed using a nut or by screwing the fastener into one of the parts being joined.

The features of each of the two fastener types are as follows.

• Bolt. Its “top” is usually hexagonal, but sometimes has four flats or is ring-shaped. To secure the bolt, a nut – a fastener with internal thread – is screwed onto it. A washer is often placed under the head to increase the contact area and prevent self-loosening.
• Screw. Thread runs along the entire length of this fastener; it is screwed not into a nut but into one of the parts being joined, which has internal thread. Unlike a bolt, a screw is not necessarily driven with a wrench – a screwdriver matched to the shape and size of the recess on the head or end can be used instead.