STAINLESS STEEL TAB WASHERS WITH ONE LONG TAB DIN 93

Tab Washers with one Long Tab DIN 93 — DIN 93 provides a simpler, lighter version of the mechanical tab-locking principle used across this family of washers - a single long tab, bent up against a flat on the hex nut or bolt head after tightening, which physically blocks the nut from turning back without the tab first being straightened out. That is a genuinely positive lock rather than a frictional one: unlike a spring or toothed washer, which can theoretically still work loose gradually under enough vibration, a properly bent DIN 93 tab makes rotation mechanically impossible until someone deliberately straightens it, which is exactly why tab washers are specified on joints where reliability matters more than convenience. It differs from DIN 432 in where the tab actually engages - DIN 93's tab is intended to bear against a flat on the nut itself, whereas DIN 432's external tab is bent against an adjacent edge of the surrounding component rather than the nut - so the choice between the two often comes down to which reference surface is actually available in the assembly. For higher-security applications, DIN 463 adds wing tabs on top of the same long-tab principle, giving a second point of engagement where a single tab alone is not considered secure enough. Material selection tracks the joint's environment and duty: carbon steel is the standard choice for general machinery and structural fixings, while A2 (304-equivalent) stainless is worth specifying for outdoor or washdown assemblies, and A4 (316-equivalent) is the right call for marine, coastal, or chemically aggressive conditions, since a corroded or weakened tab defeats the whole point of a mechanical lock. To specify correctly, match the bore to the nut size and confirm the tab length is sufficient to reach a nut flat once the assembly is fully tightened, checking clearance around the joint for the tab to be bent into position.

FAQs
How does DIN 93 provide locking?
The tab is bent up against one of the flats of the hex nut after tightening, physically blocking the nut from turning without the tab first being straightened, giving a positive mechanical lock rather than a frictional one.

How does DIN 93 differ from DIN 432?
DIN 93's tab is typically intended to engage a flat on the nut itself, while DIN 432's external tab is bent against an adjacent edge of the surrounding component rather than the nut.

How does DIN 93 differ from DIN 463?
DIN 463 adds wing tabs to the long tab for a second point of engagement, giving stronger locking security than the single-tab DIN 93 design.