Definition

1. Noun:
   • A supplementary nut that is screwed down onto a primary nut to prevent it from loosening. It is a type of fastener used to secure another nut in place, typically by applying friction or mechanical interference.

Usage

• A locknut is used in mechanical and engineering contexts to prevent vibration or rotation from causing a primary nut to become loose. It is threaded onto the same bolt or stud after the primary nut and is tightened against it.

Examples

• Noun:
  • Always install a locknut on the axle to secure the wheel bearing.
  • The assembly requires a locknut to prevent the main fastener from backing off under stress.
  • Check that the locknut is properly torqued against the primary nut.

Advanced Usage

• "Jam nut": A specific, thinner type of locknut. When used, the thin jam nut is tightened first against the workpiece, then the standard (primary) nut is tightened down onto it, jamming the two nuts together.
  • Use a jam nut as a locknut in applications where space is limited.

Variants and Related Words

• Jam nut (n): A thin locknut, often used interchangeably with "locknut" in some contexts, though technically a subtype.
• Prevailing torque nut (n): A locknut that has a design (like a nylon insert or deformed threads) to create friction and resist loosening.
• Stover nut (n): A specific brand name for a type of prevailing torque locknut.

Synonyms

• Check nut: Another term for a locknut, emphasizing its function of checking or stopping movement.
• Stop nut: A nut designed to lock in position and stop further rotation.

Notes

• The term locknut refers specifically to the secondary, locking component. It is not used to describe a single, self-locking nut (like a nylon insert nut) unless that nut is being used in a secondary, jamming role. The primary function is to lock another nut.

Noun

1. supplementary nut that is screwed down on a primary nut to prevent it from loosening