| Type | Features | Common standards | When to use |
|---|---|---|---|
| Hex nut | Standard height, the most general-purpose | DIN 934 / ISO 4032 | General fastening, first choice |
| Thin hex nut | About half the height | DIN 439 / ISO 4035 | Limited space; or as the jam nut in a double-nut lock |
| Nylon insert lock nut | Nylon ring in the top; locks by friction | DIN 985 / ISO 10511 | Vibration; the nylon ring has limited heat resistance, so use another locking method in high-temperature locations |
| Flange nut | Integral washer face at the bottom (often serrated) | DIN 6923 / ISO 4161 | No separate washer needed, large contact area, good for thin sheet |
| Threaded insert | Pressed or heat-staked into plastic or soft material to provide a metal internal thread | Type depends on the manufacturer; no single universal standard | Plastic or 3D-printed parts that must be assembled and disassembled repeatedly |
Metric nuts are written as M diameter-P pitch; for example M14-P1.0 is an M14 fine thread. If no P is given, it usually means coarse thread (e.g. M10 = M10-P1.5). Inch nuts are written as diameter-threads per inch, e.g. 1/4-20. A wrong pitch is the most common reason for returns, so always check the P value on fine-thread items. Threaded inserts are also marked with their outer diameter and length (e.g. M3*4, OD 4.6).
Light vibration → spring lock washer; noticeable vibration → nylon insert lock nut or tooth lock washer; repeated disassembly → nylon insert lock nut (note that the locking force drops after repeated use); high temperature → avoid nylon rings and use a double nut or tooth lock washer instead. For a comparison of washer types see washer types compared.
Common options are zinc plated, carbon steel, 304 stainless steel, 316 stainless steel, brass and aluminum. Choose stainless for corrosion resistance; brass is an option where conductivity or non-magnetic properties are needed.
Click a size to open its product page (price and stock status); lists update automatically with our stock. For shaft nuts such as bearing lock nuts and clamping nuts, search the interactive catalog.