Marine Fasteners RP-1421 5/16in Lock Washers 100-Pack

The Marine Fasteners RP-1421 is a 5/16-inch split lock washer crafted from 18-8 stainless steel, engineered to keep fasteners secure in demanding marine and outdoor environments. Each pack contains 100 washers, making it ideal for both professional installers and serious DIYers who need a reliable bulk supply.

Split lock washers — also known as spring lock washers — feature a helical cut that generates axial spring tension between the fastener head and the mating surface when tightened. This tension resists loosening caused by vibration, hull movement, and engine torque, providing a dependable hold in high-stress applications.

Key Features:

• Size: 5/16 inch — fits standard 5/16" bolts and screws
• Material: 18-8 stainless steel for strong corrosion resistance in marine, saltwater, and outdoor environments
• Split-ring design: Creates spring tension that resists vibration-induced loosening
• Quantity: 100 washers per pack — convenient bulk packaging for larger projects
• Versatile use: Suitable for marine hardware, boat deck fittings, dock assemblies, automotive, and general mechanical applications
• Compatible with standard 5/16" bolts, screws, and nuts

The Marine Fasteners RP-1421 lock washers are a cost-effective solution for any application where fastener security and corrosion resistance are critical. Simply place the washer between the fastener head (or nut) and the mounting surface, then tighten until the washer flattens and its edges engage both surfaces to resist rotation.