STAINLESS STEEL AFNOR FLAT WASHERS NFE 25-514 TYPE LL

AFNOR Flat Washers NFE 25-514 Type LL — Type LL sits at the top of the NFE 25-514 progression, giving the widest bearing footprint available in the AFNOR flat washer range for a given bolt diameter - the size to reach for specifically when even Type L does not provide enough load-spreading area, typically on the softest clamped materials or the largest, most oversized clearance holes the application presents. It works on the same basic principle as any large-diameter flat washer: the wider the washer, the more the fastener's clamping force is spread across the surrounding material, reducing the local bearing pressure and the risk of the fastener embedding, crushing, or pulling through whatever it is tightened against. It plays a broadly similar role to DIN 9021 or ISO 7093-1 in their respective standards systems, but all three are dimensioned independently, so they should be treated as functionally similar rather than dimensionally interchangeable - checking the actual outside diameter and thickness against the relevant table remains necessary before substituting one for another. It is not, on its own, a structural washer: its large bearing area is genuinely useful for spreading load over soft or thin materials, but for formally designed structural steelwork connections, a washer specified to the relevant structural standard, such as DIN 7989, should be used instead, with the structural design requirement confirmed before defaulting to a large general-purpose washer like Type LL. Material selection follows the pattern of the rest of the range: mild steel with plating for general indoor use, A2 (304-equivalent) stainless as the standard outdoor and washdown upgrade, and A4 (316-equivalent) specifically for coastal, marine, or chemically aggressive environments, where a washer this size presents a correspondingly large surface for chloride attack if the wrong grade is chosen. To specify correctly, match the bore to the bolt diameter and confirm the application genuinely requires the widest series in the range rather than the smaller L, M, or Z types.

FAQs
How does Type LL compare to a DIN 9021 or ISO 7093-1 washer?
All three serve a similar large-diameter, load-spreading role, but each is governed by its own standard with a separate dimensional table; they should be treated as functionally similar rather than dimensionally interchangeable.

Is Type LL suitable for structural applications?
Its large bearing area is useful for soft or thin materials, but for formally designed structural steelwork connections, a washer specified to the relevant structural standard, such as DIN 7989, should be used instead.

When would Type LL be chosen over Type L?
Where even the L series does not provide sufficient bearing area, typically on the softest materials or largest clearance holes within the application range covered by NFE 25-514.