M5 x 18mm Mudguard/Penny Repair Washer – DIN 440, BZP

High Quality Material & Finish

• Bright zinc plating (BZP) for protection: DIN 440 mudguard/penny washers are available in various materials and finishes. A bright zinc plated finish is popular because zinc corrodes about 100 times more slowly than most metals. This plating forms a barrier that resists oxidation, making the washers suitable for humid or moist environments while giving them a shiny, polished appearance. Zinc plated fasteners are also strong and durable.
• DIN 440 standard for timber and construction: The DIN 440 specification defines wood construction washers with large outside diameters. These washers are designed to spread the force of a bolt or nut over a greater surface area, protecting timber or other soft materials from being crushed or splitting. The increased bearing surface also accommodates movement in wood as it expands or contracts due to humidity.

Design & Performance

• Large diameter “penny” design: Penny (or mudguard/repair) washers have a wide outside diameter relative to their hole size. This large surface area spreads the tightening load, preventing the fastener from pulling through soft materials such as rubber or timber. It also helps to cover and reinforce enlarged or worn holes.
• Bright zinc plating improves corrosion resistance: As noted above, zinc plating offers good corrosion resistance, making these washers suitable for both indoor and outdoor use. The polished finish gives an attractive appearance while still being cost effective.
• Versatile load spreading ability: The washers are typically used with threaded fasteners to distribute the load over a larger area than conventional flat washers. They prevent bolt heads from crushing soft materials or pulling through and provide a long lasting repair for oversized holes.

Typical Applications

• Soft material fastening: Ideal for timber, plastics, rubber and sheet metal where standard washers might pull through. The automotive industry uses them on mudguards to stop small bolt heads pulling through rubber.
• Repair and reinforcement: Often called repair washers because they can cover damaged or enlarged holes and restore a secure fixing.
• Heavy duty construction: DIN 440 Type R washers are commonly specified for timber construction and other structural applications.

Ease of Use & Installation

• Simply slide the washer over the bolt or screw so that it sits between the fastener and the material being joined.
• Ensure the washer’s inside diameter matches the fastener diameter (e.g. use an M8 washer with an M8 bolt) and that the outer diameter covers the hole.
• Tighten the fastener as normal — the washer will distribute pressure and protect the material.
• For repair work, choose a washer with a large enough outer diameter to cover the damaged area.

Summary

PENNY REPAIR MUDGUARD DIN 440 washers combine the load spreading performance of large diameter mudguard/penny washers with the corrosion resistant, polished finish of bright zinc plating. Designed according to DIN 440 standards for wood and timber construction, these washers prevent bolt heads from pulling through soft materials, reinforce enlarged holes and are suitable for both indoor and outdoor environments.