STAINLESS STEEL HEXAGON CASTLE NUTS THIN TYPE DIN 937

Hexagon Castle Nuts Thin Type DIN 937 — DIN 937 carries the same castellated crown and split-pin locking principle as the full-height DIN 935 — slots machined into the top face align with a transverse hole in the bolt or shaft, and a split pin passed through both gives a positive mechanical lock that can't work loose the way friction-based locking can — but in a lower-profile thin nut body, for applications where axial space is genuinely too tight for the taller DIN 935. That reduced height comes at the cost of reduced thread engagement compared with the full-height version, so DIN 937 generally carries less load capacity for the same nominal diameter; the application's load requirements, not just the available clearance, should determine which type actually gets specified, since defaulting to the thin type purely out of habit can under-engineer a joint that has room for the full-height version. As with DIN 935, the pin is what actually locks the assembly — the nut is tightened until the slots align with the shaft's cross-hole, and a split pin passed through both prevents rotation regardless of vibration or shock loading; fitted without the pin, it's just a plain thin nut relying on friction alone, which defeats the purpose of specifying a castellated type in the first place. Typical applications mirror DIN 935's safety-critical rotating and axle duty, but specifically where the assembly's design has already fixed a tighter axial envelope than a full-height castle nut would fit into. A2 stainless suits general machinery applications; A4 is worth the extra cost for automotive, marine, or outdoor exposure where the joint will be difficult to inspect and replace over its service life. Sizing follows the mating bolt and shaft's diameter, pitch, and the position of the cross-hole that the pin will pass through, exactly as with DIN 935.

FAQs
Should axial space alone decide between DIN 935 and DIN 937?
No — clearance is the reason thin castellated nuts exist, but the joint's load requirement should be checked first; if there's enough room for the full-height DIN 935, it generally gives more margin than defaulting to the thin type out of habit.

Does the thin body make the split pin harder to fit?
No, the slot and cross-hole alignment principle is identical to DIN 935; the reduced height affects thread engagement and load capacity, not the mechanics of aligning and fitting the split pin.

How is the split pin fitted to a DIN 937 nut?
As with DIN 935, the nut is tightened until the slots align with a transverse hole in the bolt or shaft, and a split pin is passed through both to mechanically lock the assembly against rotation.

Is DIN 937 suitable for the same load-bearing applications as DIN 935?
Because of its reduced thread engagement, DIN 937 generally carries less load capacity than the full-height DIN 935; the application's load requirements should determine which type is specified.