Prevailing Torque Lock Nuts, Nylon Insert Lock Nuts and All-Metal Lock Nuts

A prevailing torque lock nut is a nut designed to resist loosening through friction generated by a locking feature. The locking feature may be a non-metallic insert or an all-metal deformed thread section. The prevailing torque is the friction torque present before the nut contacts the bearing surface.

A nylon insert lock nut uses a non-metallic collar at the top to create prevailing torque friction. An all-metal lock nut relies on controlled thread deformation or a mechanical locking feature in the metal nut body. They are not interchangeable. Selection depends on the applicable standard, temperature, chemical exposure, and reuse requirements.

Regular, high and thin lock nuts have different nut heights. A regular nut has a standard height range. A high nut has increased height for greater thread engagement. A thin nut has reduced height and is used where space is limited. They are not interchangeable for the same application.

Buyers should provide lock nut type, locking method, applicable standard, metric or inch thread, diameter, thread pitch or TPI, regular or high or thin style, material, property class, insert type if applicable, surface finish, mating bolt standard and grade, temperature and chemical exposure, reuse requirements, quantity, packing and inspection documents.

Nylon inserts have temperature limitations. The specific material, application temperature and performance requirements must be confirmed. All-metal lock nuts may be considered for higher temperature applications, but suitability depends on the exact grade, standard and application conditions.

No. All-metal lock nuts are not automatically suitable for every high-temperature application. The exact material, locking design, applicable standard and service conditions must be confirmed. General claims about high-temperature capability cannot substitute for project-specific verification.

Reuse depends on the nut type, applicable standard, and the buyer's specific reuse requirements. Not all lock nuts are designed for reuse. Prevailing torque performance after repeated use should be confirmed against the applicable test standard.

Prevailing torque is the friction torque generated by the locking feature before the nut contacts the bearing surface. Installation torque (tightening torque) is the total torque applied to achieve clamp force, which includes prevailing torque plus bearing surface friction. They are not the same parameter.

Lock nut performance depends on the mating bolt. The bolt grade, surface finish, coating, thread tolerance and hardness all affect the prevailing torque and locking behaviour. A lock nut tested on one bolt condition may not perform identically on another.

No. Metric and inch thread systems are different. Thread diameter, pitch and thread form are not interchangeable.

No. Coarse and fine threads have different pitches, depths and strength characteristics. They are not interchangeable.

DIN 985 and ISO 7040 are related but may have differences in dimensions, material requirements and performance specifications. Buyers should confirm the applicable standard, version, dimensions and requirements for their specific product.

A serrated flange nut has serrations on the flange bearing surface designed to resist loosening through mechanical engagement with the mating surface. A prevailing-torque flange nut has a prevailing torque locking feature in the nut body. They use different locking principles and are not automatically interchangeable.

No. A castellated nut achieves positive locking through a cotter pin or other mechanical locking device inserted through slots in the nut. It is not a prevailing-torque lock nut. The locking principle and application requirements are different.

Yes. Mixed orders can be reviewed manually when type, locking method, thread size, style, material, grade, finish, quantity, packing and inspection requirements are clear for each product type.

Depending on the item and buyer requirements, documents may include dimensional reports, material test certificates, coating thickness reports, prevailing torque test reports, proof load test reports, and pre-shipment photos.

Lead time depends on material availability, nut type, locking element type, heat treatment if applicable, coating, quantity, packing requirements and inspection requirements. Final lead time is confirmed after RFQ review.

Yes. Reference conversions can be provided, but metric and inch products are not automatically interchangeable. The original thread system, pitch or TPI, dimensions, grade, matching components and applicable standard must remain part of the RFQ review.