DIN 933 vs ISO 4017 difference (short answer)
Both are fully threaded metric hex head screws/bolts. For most commercial buys they are treated as equivalents; the practical difference is standard system (DIN vs ISO) and width across flats (WAF) on a few sizes (especially M10, M12, M14, M22). Confirm tools before substituting.
What US buyers usually mean
In US RFQs you will often see hex bolt, hex head screw, or a drawing callout like DIN 933 / ISO 4017. For metric catalogs, both DIN 933 and ISO 4017 describe a fully threaded hex head fastener (often sold as a hex head screw / hex bolt).
Partial-thread cousins are different: DIN 931 ≈ ISO 4014 (shank + thread). Do not mix full-thread and partial-thread on the same critical fit without checking length under head and grip.
DIN 933 vs ISO 4017 at a glance
| Item | DIN 933 | ISO 4017 |
|---|---|---|
| Product | Hex head, full thread | Hex head, full thread |
| Typical US wording | Hex bolt / hex head screw | Hex head screw (ISO callout) |
| Interchange | Common for commercial buying | Preferred on newer drawings |
| Watch-outs | Tool size on some diameters | Width across flats (WAF) differs for M10, M12, M14, M22 |
For most OEM/MRO buys, they are treated as the same product family—confirm WAF / wrench size when tooling is fixed, especially on M10–M14 and M22.
Related searches buyers type
- metric hex head bolt 304 stainless
- DIN 933 A2-70
- ISO 4017 hex screw
- hex bolt vs hex head screw metric
- fully threaded hex bolt M6 M8 M10
How to order on Pisenfasten
- Open hex head screws (our metric 304 / A2-70 line)
- Match thread × length to the drawing
- Pair with hex nuts and flat washers when the BOM requires a kit stack
- Need 316 / A4 or a partial-thread DIN 931 style? Contact sales with the drawing
- Buying cartons for resale or replenishment? Review the quote-specific Wholesale terms
Also see: A2-70 vs A4-80 and our parametric catalog.
RFQ checklist
- Standard: DIN 933 or ISO 4017 (pick one primary)
- Thread × length (under head)
- Material / class: e.g. 304 A2-70 (or 316 / A4 if specified)
- Full thread vs partial thread
- Docs: MTC, RoHS, REACH
- Qty + ship-to country
FAQ
Q: Can I substitute ISO 4017 for DIN 933?
A: Usually yes for commercial grades when diameter, length, pitch, and property class match. Recheck WAF on M10/M12/M14/M22 if sockets/tools are already purchased.
Q: Why do Americans say “hex bolt” but catalogs say “hex head screw”?
A: Trade language differs. In metric DIN/ISO catalogs, fully threaded hex heads are commonly listed as hex head screws; US buyers still search “hex bolt.”
Q: Do you stock 304 stainless hex heads?
A: Yes — browse hex head screws and filter by thread size.
Q: What about DIN 931 / ISO 4014?
A: Those are partial-thread hex bolts. Tell sales if the drawing shows an unthreaded shank.