STAINLESS STEEL WASHERS FOR CLEVIS PINS (MEDIUM) DIN 1440

Washers for Clevis Pins (Medium) DIN 1440 — A clevis (fork) joint does not use a thread at all - the pin is held in place by a split pin through a cross-hole near its end, and DIN 1440 is the washer that sits between that split pin and the clevis fork, rather than under a bolt head or nut the way most washers in this range do. Without it, the split pin would bear directly on the fork itself, concentrating load onto a small area of the fork material and risking wear or deformation around the pin hole over repeated use; the washer gives a defined, flat bearing surface that spreads that load properly and protects the fork from that kind of wear. DIN 1440 is specifically the medium-tolerance series within DIN's clevis pin washer range, sized to match standard clevis pin diameters and their typical head bearing dimensions at a moderate fit - distinct from the coarser DIN 1441, which covers the same pin sizes at a wider tolerance. The choice between the two comes down to the fit specified for the clevis pin in the assembly rather than a general preference, so it is worth checking the pin's tolerance class before defaulting to the medium series. These washers turn up in linkages, lifting equipment, agricultural machinery, and any pinned (rather than threaded) mechanical joint, wherever a clevis pin and split pin combination is the specified fastening method. Material selection is generally driven by the mechanical duty and environment: carbon steel suits general indoor machinery, while A2 (304-equivalent) stainless is the standard upgrade for outdoor or washdown equipment, and A4 (316-equivalent) is worth specifying for agricultural, marine, or coastal equipment where the pin and washer see regular exposure to moisture, mud, or salt. To choose correctly, match the bore to the clevis pin diameter and confirm the medium series is genuinely specified rather than the coarse DIN 1441 alternative.

FAQs
Why does a clevis pin need a specific washer?
The washer sits under the split pin, between it and the clevis fork, preventing the split pin from bearing directly on the fork and providing a defined bearing surface sized specifically to clevis pin diameters.

How does DIN 1440 differ from DIN 1441?
DIN 1440 is the medium series, while DIN 1441 is the coarse series, differing in tolerance for the same nominal clevis pin diameter. The correct one depends on the fit specified for the pin in use.

How do I choose the correct DIN 1440 washer?
Match the bore to the clevis pin diameter and confirm the medium series is specified rather than the coarse DIN 1441 alternative.