316/A4 Stainless Metric Flat Washers

316 Stainless Steel (A4) DIN 125A Metric Flat Washers

Flat washers are one of the most important and most misunderstood components in any fastening system. Our DIN 125A flat washers are precision manufactured from A4 grade 316 stainless steel, giving you reliable load distribution, surface protection, and unmatched corrosion resistance in harsh marine and outdoor environments.

DIN 125A washers are the standard flat washer for metric fasteners, designed with controlled inside diameter, outside diameter, and thickness so they fit properly under bolt heads and nuts without distortion or slop. This ensures consistent clamping force and prevents fastener heads from digging into softer materials like aluminum, fiberglass, wood, or composites.

These washers are widely used in:

• Marine and offshore hardware
• Boatbuilding and refits
• Dock and marina construction
• Machinery and mechanical assemblies
• Sheet metal and aluminum structures
• Wood and composite construction
• Automotive and trailer hardware

Wherever a bolt or screw bears against a surface, a properly sized flat washer helps protect the material and preserve the integrity of the joint.

Why DIN 125A Matters

DIN 125A defines the exact geometry, flatness, and thickness of the washer so that it performs consistently across all sizes. These are not generic punched washers. They are engineered metric components that distribute load evenly and maintain proper fastener preload.

Using the correct DIN washer prevents cupping, galling, and localized stress that can lead to loosening or material failure over time.

Material: A4 / 316 Stainless Steel

These washers are made from A4 stainless steel, also known as 316, the preferred alloy for marine and corrosive environments.

• Exceptional resistance to rust and pitting
• Highly resistant to saltwater and chlorides
• Excellent mechanical strength
• Long service life outdoors and in washdown areas
• Non-magnetic in most conditions

This is the same stainless used in boat hardware, fasteners, and offshore equipment, and it significantly outperforms A2, 18-8, and 304 stainless in coastal and saltwater exposure.