Penny / Mudguard Washers M3–M10 — A2 Stainless DIN 9021

Why choose these Penny / Mudguard Washers

Our Penny / Mudguard Washers are pressed from A2 (18/8) stainless steel to DIN 9021 — the European standard for large-OD flat washers, also known as penny washers, repair washers or mudguard washers. The oversized outside diameter (typically two to three times the bolt diameter) spreads load over a much wider area than a standard form A washer, which makes them ideal for soft timber, plastic, sheet metal, oversized clearance holes, or repairing holes that have been enlarged or worn. A2 stainless gives excellent corrosion resistance for general indoor and outdoor use; for marine, coastal or chloride-rich environments, our matching A4 316 penny washers are the right choice.

Sizes available

Each washer is specified by bolt size × outside diameter. Use the variation selector to choose the exact combination you need:

• M3 — 9mm or 12mm OD
• M4 — 12mm, 16mm, 20mm or 25mm OD
• M5 — 15mm, 20mm or 25mm OD
• M6 — 18mm, 24mm or 30mm OD
• M7 — 22mm OD
• M8 — 24mm or 32mm OD
• M10 — 25mm, 30mm or 40mm OD

Large sizes, sold by the box

M12 to M30 are available in full manufacturer's boxes. DIN 9021 standard OD: M12 × 37mm, M14 × 44mm, M16 × 50mm, M18 × 56mm, M20 × 60mm, M24 × 72mm and M30 × 92mm. We also stock a wider-OD pattern in M12 × 48mm, M14 × 56mm and M16 × 64mm for the heaviest load-spreading jobs.

Please note: box quantities are ordered in to your requirement rather than held on the shelf — allow up to 2 weeks for delivery. Every pack of 10 or 20 is in stock for same-day dispatch as usual.

Pack options

M3–M10 are available in packs of 10 or 20. M12–M30 are supplied by the box (25, 50, 100 or 200 pieces depending on size).

Typical uses

• Spreading bolt load on softwood decking, fence posts, sheds and timber frames
• Garden furniture, signage and outdoor metalwork where A2 stainless is sufficient
• Mudguards, splashguards and vehicle body panels — the original “mudguard washer” application
• Repairing or reinforcing enlarged, worn or oversized clearance holes in sheet metal or panels

How to fit

Place the penny washer between the work surface and the head of the bolt (or under the nut) before tightening, ensuring the bolt sits centrally in the washer’s clearance hole. Use one washer per bolt face — combining two undersized washers is not a substitute for a correctly sized penny washer. For long-term outdoor use, pair with A2 stainless bolts and nuts to avoid galvanic corrosion.

Delivery

Same-day dispatch on orders placed before 2pm, Monday to Friday, on all pack sizes of 10 and 20. Box quantities allow up to 2 weeks. Free UK delivery on orders over £20.