Any externally threaded fastener installed by rotating its head, either into a pre-tapped hole or into material where it cuts or forms its own mating thread. Machine screws, cap screws, sheet metal screws, wood screws and self-drilling screws all fall under the word. On the shop floor the term is used loosely, but in specifications and customs classification the bolt-or-screw call depends on how the part is meant to be installed.
Print says screw into the tapped boss, so no nut, and make sure you've got at least one diameter of thread engagement.
Do not mix it up with
- Bolt: A bolt is designed to be tightened by turning a nut, not its own head.
Related terms
Bolt
A headed, externally threaded fastener meant to be tightened by turning a mating nut rather than its own head.
Cap screw
A precision-headed screw, hex or socket, made to close tolerances and usually driven into a tapped hole.
Thread-forming screw
A screw that displaces material to form its own mating thread in a plain pilot hole, without cutting chips.
Thread engagement
The axial length over which external and internal threads fully overlap, which sets stripping strength.