Technical Guide
DIN 931 vs DIN 933 Bolts
DIN 931 and DIN 933 are both hex head bolts to the same head/wrench dimensions — the difference is how much of the shank is threaded. It affects clamping behaviour, not head size or wrench fit.
The core difference
DIN 933 is a fully threaded hex bolt — the thread runs the entire length of the shank. DIN 931 is partially threaded — a plain (unthreaded) shank section sits between the head and the start of the thread, with only the last portion of the bolt threaded.
Both use the same hexagon head dimensions and the same metric thread series, so a DIN 931 and DIN 933 bolt of the same nominal diameter use the same spanner or socket.
DIN 931 vs DIN 933 at a glance
| DIN 933 (Full Thread) | DIN 931 (Partial Thread) | |
|---|---|---|
| Thread coverage | Full length of shank | Partial — plain shank + threaded tip |
| Typical use | Thin materials, nutted joints, tapped holes | Thicker clamped joints, shear applications |
| Clamping behaviour | Thread engages along full length | Plain shank carries shear load; thread only for the nut |
| Head & wrench size | Same as DIN 931 at equal diameter | Same as DIN 933 at equal diameter |
When to choose which
- DIN 933 — general-purpose fastening, thin sections, or where the full length needs to thread into a tapped hole.
- DIN 931 — thicker joints where the unthreaded shank should carry shear load rather than the thread root, or where the joint length exceeds standard thread lengths.
- Both are stocked by Kesharia across Brass, High Tensile, Stainless Steel and Mild Steel — see the related categories below for exact size ranges.
Frequently Asked Questions
Can DIN 931 and DIN 933 bolts use the same nut?
Yes — both use the same standard metric thread series at a given diameter, so the same hex nut fits either.
Which one does Kesharia stock?
Both. DIN 933 (full thread) and DIN 931 (partial thread) are stocked across Brass, High Tensile, Stainless Steel and Mild Steel — see the categories linked below for verified size ranges and finishes.
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