Prevailing Torque Nut vs. Nylon Lock Nut
Both stop a nut from vibrating loose, but only one survives high heat.
| Feature | Prevailing Torque Nut | Nylon Lock Nut |
|---|---|---|
| Locking method | Distorted all-metal threads | Nylon insert |
| Heat limit | None (all metal) | About 250°F — nylon melts |
| Reuse | A few cycles | A few cycles |
| Run-down | High drag the whole way | Drag only at the insert |
| Best for | Exhaust, engines, high heat | General vibration resistance |
Verdict
Under heat or chemicals, the all-metal prevailing torque nut is the only choice. Everywhere else, a nylon lock nut is cheaper and easier to run down.