Our metric washers distribute clamping load, protect surfaces, and lock fasteners against vibration. From plain flat washers (DIN 125) and large-diameter fender washers (DIN 9021) to spring and serrated lock washers, we stock the full washer range in steel and stainless to suit every bolted joint.

Washers - Metric Sizes

What Is a Washer?

A washer is a thin disc with a central hole placed under a bolt head or nut to spread the clamping load over a wider area, protect the mating surface, bridge oversized holes, or provide a locking function. Though simple, washers are critical to joint reliability: they prevent the fastener from digging into soft material, reduce the risk of surface damage, and in their locking forms help keep the assembly tight under vibration.

At Metric Specialties we stock the complete washer range. Flat washers (DIN 125 / ISO 7089) spread load and protect surfaces; large-diameter fender or penny washers (DIN 9021) bridge clearance holes in thin sheet; spring (split) washers (DIN 127) apply axial tension to resist loosening; and internal, external, and serrated lock washers bite into the fastener and surface to grip. Specialty forms including conical (Belleville) spring washers, hardened thick flat washers, and hinge ring washers cover high-load, structural, and pivoting applications.

Key Features and Benefits

• Load Distribution: Flat washers spread clamp force over a larger area, protecting soft or thin materials from damage.
• Vibration Locking: Spring and serrated washers apply tension or bite into the surface to resist loosening.
• Hole Bridging: Large fender washers span oversized or elongated holes in sheet and panel work.
• Surface Protection: Washers prevent marring of finished surfaces beneath the fastener head.
• High-Load Options: Hardened and conical spring washers handle structural preload and dynamic loading.

Materials and Finishes

• Carbon Steel (Zinc Plated): Standard washers for general engineering and assembly.
• Hardened Steel: Thick, heat-treated washers for high-preload structural joints.
• Spring Steel: Tempered material for spring and conical washers that must retain tension.
• Stainless Steel A2 / A4: Corrosion-resistant washers for outdoor, marine, and hygienic use.

Standards Compliance

• DIN 125 / ISO 7089 Plain flat washers.
• DIN 9021 Large-diameter (fender) washers.
• DIN 127 Spring (split) lock washers.
• DIN 6797 Serrated (toothed) lock washers.

Common Applications and Industries

Washers support bolted joints across construction, automotive, electronics, and general engineering. Flat washers spread load and protect surfaces under nuts and bolt heads everywhere fasteners are used, while large fender washers bridge oversized holes in bodywork, sheet metal, and panel assembly. Spring and serrated lock washers keep fasteners tight on vibrating machinery, engines, and equipment.

Specialty washers serve demanding roles: conical (Belleville) spring washers maintain preload on high-strength bolts subject to thermal cycling and settling, and hardened thick flat washers resist indentation under the high preload of structural steel connections in buildings, bridges, and towers. This range lets designers match load distribution, surface protection, and locking to each joint.

How to Choose the Right Washer

Identify the primary job: use a flat washer to spread load and protect the surface, a fender washer to bridge a large or elongated hole, and a locking washer where vibration resistance is needed. For high-preload structural bolts, choose a hardened thick washer to resist indentation, and for joints subject to movement, a conical spring washer to maintain clamp force.

Then match the size to the fastener and select the material and finish for the environment zinc-plated steel for general use, hardened or spring steel for load and tension, and A2 or A4 stainless for corrosion resistance. Combining a flat washer with a locking washer is common where both load distribution and vibration resistance are required.

Size Range and Availability

Available in M2 through M52 across flat, fender, spring, serrated, conical, and hardened washer types, in zinc-plated steel and A2/A4 stainless.

Why Buy From Metric Specialties

As dedicated metric fastener specialists, we hold washers in the sizes, grades, and finishes that engineers actually need, backed by clear DIN and ISO standard references so you can specify with confidence. Every item is sourced to recognised standards and quality-controlled, giving you consistent thread fit, strength, and corrosion performance across repeat orders.

Whether you need a single item for a repair or bulk quantities for production, our range, technical guidance, and fast dispatch help you find the exact fastener for the job. If you are unsure which size, grade, or finish suits your application, our team can help you match the right product to your load, environment, and standard, so your assemblies are reliable and built to last.

Frequently Asked Questions (FAQs)

1. What is a washer used for?

Washers distribute clamping load over a wider area, protect surfaces from damage, bridge oversized holes, and in locking forms help prevent fasteners loosening under vibration.

2. What is the difference between a flat washer and a spring washer?

A flat washer spreads load and protects the surface, while a spring (split) washer applies axial tension between nut and surface to resist loosening from vibration. Many joints use both together.

3. What is a serrated lock washer?

A serrated lock washer has teeth that bite into both the fastener and the mating surface, creating grip that resists rotation. Internal-tooth types hide the teeth; external-tooth types offer greater locking.

4. What is a fender or penny washer?

A fender (penny) washer has a large outside diameter relative to its hole, allowing it to bridge oversized or elongated holes and spread load across thin sheet material such as bodywork panels.

5. What is a conical or Belleville spring washer?

A conical spring washer is a cone-shaped disc that acts as a spring, maintaining tension in the joint as it flattens under load. It is used to compensate for settling and thermal movement.

6. When should I use a hardened flat washer?

Use a hardened thick flat washer under high-strength bolts and in structural joints where a soft washer would deform. The hardened material resists indentation and maintains bearing area under high preload.

7. Are your washers available in stainless steel?

Yes. We stock A2 and A4 stainless washers across most types for corrosion-resistant use in marine, outdoor, food, and chemical environments.

8. Do washers help prevent bolts loosening?

Locking washers spring, serrated, and conical types help resist loosening by applying tension or gripping the surface. Plain flat washers do not lock but improve load distribution and surface protection.

9. Which way does a spring washer go?

A split spring washer is fitted so its split edges bear against the nut and the surface. As the fastener is tightened the washer flattens, applying tension that resists loosening.

10. What sizes do you stock for washers?

We stock M2 through M52 across flat, fender, spring, serrated, conical, and hardened washer types, in zinc-plated steel and A2/A4 stainless.