Fender Washers

A fender washer’s defining feature is a genuinely large outer diameter combined with a bore only slightly larger than the bolt shank and a genuinely thin overall thickness, unlike a standard flat washer’s more modest diameter-to-bore ratio.

Here is why this matters. Because the washer is genuinely thin relative to its wide diameter, it has genuinely low bending stiffness across its span. This large diameter is what spreads clamping force over a wide area, which is the fender washer’s intended benefit, but this spreading effect genuinely depends on the substrate behind the washer providing continuous, flat support all the way to the washer’s outer edge. If the substrate has a gap, cavity, or unsupported span within the washer’s diameter, the washer can genuinely bend or dish into that gap under clamping load rather than remaining a flat, rigid load-spreading disk.

A genuine, honest limitation is worth stating plainly. Because this dishing genuinely re-concentrates the load back near the bolt exactly where the washer was meant to prevent that, buyers must confirm the substrate behind the fender washer is genuinely continuously supported across its full diameter, not simply assume that specifying a large enough diameter automatically solves a load-spreading problem regardless of what’s behind it. Where continuous support cannot be guaranteed, a genuinely thicker fender washer or an additional rigid backing plate should be specified instead, since a thin fender washer over an unsupported span can bend and fail to deliver the load distribution it was chosen for.

Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our fender washer range is manufactured and verified for diameter, bore, and thickness compliance under our ISO 9001:2015 quality system.