English
Nuts
General
A nut is a fundamental machine element that, together with a bolt, washer, and optional locking element, forms a bolted connection.
The internal thread of the nut matches the external thread of the bolt. Its outer shape is designed to allow the application of sufficient tightening torque using appropriate tools. The most common design is the hexagonal shape, which can be tightened using:
- Open-end wrenches
- Ring spanners
- Socket wrenches
In applications exposed to vibration, nuts must be secured against loosening. This can be achieved either by using self-locking nuts or additional locking elements.
Nut dimensions and materials are defined by international standards. While most nuts are mass-produced, special-purpose variants are also available, manufactured by machining for specific applications.
Materials
- Carbon steel
- Hardened steel
- Stainless steel (A2)
- Acid-resistant stainless steel (A4)
- Brass
- Aluminum
- Chemically resistant plastic (PA)
Property classes
- 5.0
- 8.0
- 10.0
Types
- DIN 934 – hex nut
- DIN 1587 – high dome nut (cap nut)
- DIN 917 – low dome nut
- DIN 315 – wing nut
- DIN 439 B – low (jam) nut
- DIN 6334 – coupling nut
- DIN 980 V – all-metal self-locking nut
- DIN 985 – nylon insert lock nut
- DIN 6923 – flange nut (serrated or non-serrated)
Flange nuts (DIN 6923) are commonly used in mechanical engineering applications, such as automotive and elevator systems. The integrated flange allows for higher tightening torque, while the serrated version improves joint security by increasing resistance to loosening.
