316 Stainless Cast Marine Boat Hardware

Product Overview

These precision-cast components—including cleats, hinges, latches, winches, and rail fittings—are engineered to withstand the punishing marine environment, where saltwater, UV radiation, and constant vibration threaten conventional metal hardware. Unlike 304 stainless steel alternatives, our 316 stainless steel hardware provides long-term performance in coastal and offshore applications, reducing maintenance costs and ensuring safety at sea. With ABS Type Approval and compliance with ASTM A351 standards, our marine hardware meets the stringent requirements of classification societies and boat builders worldwide, delivering both functional reliability and polished appearance.

Material

Our marine hardware is cast from 316 stainless steel (UNS S31600), a molybdenum-alloyed austenitic stainless steel formulated for extreme corrosion resistance. Its chemical composition, strictly controlled per ASTM A351, includes 16.5-18.5% chromium, 10.0-13.0% nickel, and 2.0-2.5% molybdenum—elements that create a passive oxide layer resistant to chloride attack. Carbon content is limited to ≤0.07% to prevent intergranular corrosion during welding, while sulfur (≤0.015%) and phosphorus (≤0.040%) are minimized to enhance toughness. This material achieves a tensile strength of 70 ksi (485 MPa), yield strength of 30 ksi (205 MPa), and 35% elongation, providing the strength to withstand heavy loads and impacts while maintaining ductility. Each casting undergoes ultrasonic testing to ensure internal integrity, with material certificates traceable to the melt lot.

Features

Saltwater Corrosion Resistance

The molybdenum-rich alloy resists pitting and crevice corrosion in seawater environments, with field tests showing minimal degradation after 5 years of continuous saltwater exposure. Electropolished finishes further enhance corrosion resistance, passing 400-hour salt spray testing per ASTM B117 with no visible rust or pitting.

UV and Weather Resistance

Specialized passivation treatments and optional powder coating protect against UV degradation, maintaining mechanical properties and appearance even in tropical climates. Hardware retains 95% of tensile strength after 2,000 hours of accelerated weathering testing.

High-Strength Connections

Precision casting ensures consistent mechanical properties, with cleats and winches rated for working loads up to 5,000 lbs (22.2 kN) and ultimate breaking strengths exceeding 15,000 lbs (66.7 kN)—critical for safe mooring and towing operations.

Aesthetic and Functional Design

Smooth surface finishes (Ra 0.8-1.6 μm) reduce marine growth adhesion and simplify cleaning, while ergonomic designs facilitate easy operation even with gloved hands. Cast-in features like drainage holes prevent water trapping and subsequent corrosion.

Custom Service

We specialize in custom marine hardware solutions, collaborating with naval architects and boat builders to develop components that meet specific design and performance requirements. Our in-house engineering team provides 3D modeling and FEA analysis to validate structural integrity, with prototype castings available in 4-6 weeks. Material options include 316L stainless steel for enhanced weldability in custom fabrications and duplex stainless steel for extreme load applications. Finish options range from satin polish to mirror finish, with custom colors available through powder coating. Production capabilities support both small-batch custom runs (10-50 pieces) and large-scale OEM production (1,000+ pieces monthly). All custom hardware undergoes hydrostatic testing (where applicable) and salt spray testing to verify performance, with full documentation including material certificates, test reports, and ABS product design assessment (PDA) certificates valid for 5 years. We also offer laser engraving for branding and part numbering, ensuring traceability throughout the product lifecycle.