Fender Washer

A fender washer is a plain washer with a large outside diameter relative to its hole. It is used to spread bearing pressure over thin sheet, softer material, enlarged holes, or repair areas. This product is a component in the fabricated metal product manufacturing industry. Buyers should specify the standard series, nominal hole, outside diameter, thickness, hardness, material, and finish. Safety and load values must come from the selected product standard, approval, drawing, or test report; they cannot be inferred from appearance or nominal size. The RFQ should also state quantity, packaging, inspection, and traceability requirements. The applicable standard is ISO 7093-1:2000, which provides dimensions for large-series washers. Materials on file include steel and stainless steel. The working principle is that the enlarged bearing area lowers local contact pressure, but joint capacity still depends on washer stiffness and the supported material. Always verify model-specific values and standards with the legal manufacturer or supplier.

The enlarged bearing area of a fender washer reduces the local contact pressure on the supported surface. This is beneficial when the mating material is thin, soft, or has an oversized hole. However, the overall joint capacity is not solely determined by the washer's size; it also depends on the washer's stiffness and the strength of the material it supports. The washer must be thick and hard enough to distribute the load without excessive deformation. The actual load capacity must be verified through the product standard, drawing, or test report, as it cannot be inferred from nominal dimensions alone.