A4 (316) Marine Grade Stainless Steel Fasteners

91 products

A4 (316) is marine grade stainless steel. The molybdenum in the alloy resists the chloride pitting that attacks ordinary stainless in salt air, so A4 is the grade to specify anywhere salt, chlorine or constant damp is part of the environment.

This collection brings together every A4 (316) fastener Simfix stocks, covering hex bolts, carriage bolts, socket caps, machine screws, wood screws, self-tapping screws, nuts and washers, all manufactured to DIN, ISO or BS standards.

When to choose A4 (316)

  • Boats, jetties, pontoons and rigging hardware
  • Coastal buildings, balconies and anything within reach of salt spray
  • Swimming pools and changing rooms, where chlorine is present
  • Bathrooms, wet rooms and kitchens that stay humid

When A2 (304) is enough

For indoor work, workshops, and garden structures away from the coast, A2 (304) stainless steel gives full corrosion resistance at a lower cost. A4 is worth the uplift where chlorides are present, not as a blanket upgrade.

Every size is available in DIY and Trade pack quantities.