Types of Nuts and Their Uses (with Pictures)
Every nut family with pictures — hex to wing to lock — and which bolt each one belongs on.
Lock Nut
A nylon insert grips threads against vibration.
Best for: Engines, trailers, anything that shakes
T-Nut
A pronged tee that embeds in wood for machine threads.
Best for: Furniture, jigs, climbing walls
Acorn Nut
A domed cap that finishes and protects threads.
Best for: Railings, playgrounds, visible ends
Spring Steel Nut
A spring clip that threads onto thin panels.
Best for: License plates, trim, thin-sheet fastening
How to Choose
Also in the toolbox
- Combination wrench set (SAE and metric) — fits every hex above
- Nut and bolt thread checker — identifies mystery nuts in seconds
FAQ
What is a lock nut and how does it work?
The common nyloc has a nylon ring that squeezes the bolt threads, adding friction that resists vibration loosening. Prevailing-torque (all-metal) nuts do the same with distorted threads for high heat where nylon would melt.
Can you reuse a nyloc nut?
Once or twice in non-critical joints — the nylon deforms a little every time. For wheels, suspension, engines, and anything whose failure hurts, always use a fresh lock nut.