Marine Fasteners RP-1353 Nylon Insert Lock Nut 1/2-13 UNC Stainless Steel 25-Pack

The Marine Fasteners RP-1353 is a stainless steel nylon insert lock nut (also known as a nylock nut) in a 1/2-13 UNC thread size, sold in a convenient 25-piece pack. Designed specifically for demanding marine environments, these lock nuts provide reliable, vibration-resistant fastening for boat hardware, deck equipment, and engine room applications.

Key Features:

• Nylon insert locking mechanism — the nylon collar deforms as the bolt threads through, creating friction that prevents the nut from loosening under vibration or dynamic loads
• Stainless steel construction — resists corrosion in saltwater, splash zones, and high-humidity marine environments
• 1/2-13 UNC thread — coarse thread pitch compatible with standard 1/2-inch bolts and threaded rod
• Hex nut profile — installs with standard 3/4-inch wrench or socket
• 25-piece pack — ideal for maintenance, repair, and new installations requiring multiple fasteners

These nylock lock nuts are well-suited for securing deck hardware, engine mounts, pumps, through-hull fittings, and other onboard components where staying tight is critical. The nylon insert is considered a prevailing-torque, single-use locking feature — replace the nut if removed and refastened in critical applications.