Stainless Steel Lock Nuts
What are stainless steel lock nuts? Stainless steel lock nuts resist loosening from vibration through a nylon insert, distorted threads, or an attached washer. Made from 18-8, 304, and 316 stainless, plus A2 and A4 metric, they hold their grip and resist rust in wet, outdoor, and high-vibration conditions where a standard nut could back off.
Stainless Steel Lock Nuts
Nylon Insert Lock Nuts
Hex nuts in 18-8 and 316 stainless with a nylon collar that grips the bolt threads to prevent loosening from vibration.
Nylon Insert Jam Lock Nuts
Low-profile nylon insert lock nuts in 18-8 and 316 stainless that combine a jam nut's thin height with vibration-resistant locking.
Keps K-Lock Nuts
Hex nuts in 304 and A2 stainless with an attached free-spinning lock washer that speeds assembly while resisting loosening.
-min.jpg?ts=1757453413 "Two Way Lock Nuts")
Two Way Lock Nuts
All-metal lock nuts in 18-8 and 316 stainless that thread and lock from either side for reusable, high-heat, vibration-resistant fastening.
-min.jpg?ts=1757453418 "Castle Nuts")
How to choose a lock nut style
Different locking methods suit different jobs. Nylon insert nuts use a nylon collar to grip the threads and are the most common all-purpose lock nut, though the nylon limits temperature. Keps nuts have a captive washer for fast assembly. Two-way lock nuts are all-metal and reusable. Match the method to your vibration, heat, and reusability needs, and the grade to the environment, with 304 or A2 for general use and 316 or A4 for coastal and saltwater exposure.
Lock nut types
- Nylon insert lock nuts: nylon collar grips the threads to resist loosening.
- Nylon insert jam lock nuts: low-profile nylon insert nut for tight clearances.
- Keps K-lock nuts: attached free-spinning washer speeds assembly.
- Two way lock nuts: all-metal locking that can thread from either side.
Common applications for stainless lock nuts
- Machinery and equipment under vibration
- Automotive, trailer, and marine assembly (316 or A4)
- Outdoor structures and railings
- Any joint that must not loosen over time
Pair these with matching stainless bolts, or add a stainless lock washer under a standard nut, and browse every lock nut style on the main lock nuts category.
Stainless Steel Lock Nuts FAQ
What grades do lock nuts come in?
18-8, 304, and 316 stainless, plus metric A2 and A4. A2 is comparable to 304 and A4 to 316.
Are nylon insert lock nuts reusable?
They can be reused a few times, but the nylon wears and grips less each time. For a critical joint, use a fresh nut.
What is the temperature limit for nylon insert nuts?
The nylon insert softens with heat, so for high-temperature use choose an all-metal lock nut such as a two-way style instead.