Technically reviewed by Vincent, Founder at HEXVARO
Last reviewed
Search DIN and ISO numbers
25 standards listed.
| Product | DIN | ISO / EN | What changes | Details |
|---|---|---|---|---|
| Hex bolt, partial thread | DIN 931 | ISO 4014 | Wrench size changes at M10 (17→16), M12 (19→18), M14 (22→21) and M22 (32→34). | Open |
| Hex bolt, full thread | DIN 933 | ISO 4017 | Wrench size changes at M10 (17→16), M12 (19→18), M14 (22→21) and M22 (32→34). | Open |
| Hex bolt, partial thread, fine pitch | DIN 960 | ISO 8765 | Wrench size changes at M10 (17→16), M12 (19→18), M14 (22→21) and M22 (32→34). | Open |
| Hex bolt, full thread, fine pitch | DIN 961 | ISO 8676 | Wrench size changes at M10 (17→16), M12 (19→18), M14 (22→21) and M22 (32→34). | Open |
| Hex nut | DIN 934 | ISO 4032 (coarse), ISO 8673 (fine) | Wrench size changes at M10 (17→16), M12 (19→18), M14 (22→21) and M22 (32→34). ISO nuts are taller at most sizes, such as M16: 13→14.8 mm. | Open |
| Thin hex nut | DIN 439 | ISO 4035 (coarse), ISO 8675 (fine) | Check height, wrench size and chamfer. | Open |
| Nylon-insert lock nut, low | DIN 985 | ISO 10511 | Check height. | Open |
| Nylon-insert lock nut, standard | DIN 982 | ISO 7040 (coarse), ISO 10512 (fine) | Wrench size and height change at several sizes. | Open |
| All-metal lock nut | DIN 980 | ISO 7042 (coarse), ISO 10513 (fine) | Wrench size changes at M10, M12 and M14. | Open |
| Hex flange nut | DIN 6923 | EN 1661 (ISO 4161) | Check flange, height and serration. | Open |
| Socket head cap screw | DIN 912 | ISO 4762 (coarse), ISO 12474 (fine) | Key dimensions match. | Open |
| Countersunk socket screw | DIN 7991 | ISO 10642 | Check head angle and diameter. | Open |
| Set screw, flat point | DIN 913 | ISO 4026 | No significant change. | Open |
| Set screw, cone point | DIN 914 | ISO 4027 | No significant change. | Open |
| Set screw, dog point | DIN 915 | ISO 4028 | No significant change. | Open |
| Set screw, cup point | DIN 916 | ISO 4029 | No significant change. | Open |
| Hex flange bolt | DIN 6921 | EN 1665 (ISO 4162) | Check flange diameter, head height and thread length. | Open |
| Flat washer | DIN 125-A / 125-B | ISO 7089 / ISO 7090 | Key dimensions match. Hardness changes from 140 HV to 200 HV. | Open |
| Large flat washer | DIN 9021 | ISO 7093 | Check outer diameter. Hardness changes from 140 HV to 200 HV. | Open |
| Small flat washer | DIN 433 | ISO 7092 | Hardness changes from 140 HV to 200 HV. | Open |
| Pan head tapping screw | DIN 7981 | ISO 7049 | Head dimensions change. ST 3.9 is not in the ISO standard. | Open |
| Countersunk tapping screw | DIN 7982 | ISO 7050 | Head dimensions change. | Open |
| Hex head tapping screw | DIN 7976 | ISO 1479 | Check head dimensions. | Open |
| Spring lock washer | DIN 127 | No ISO equivalent | Still ordered as DIN 127. | Open |
| Threaded rod | DIN 976-1 (formerly DIN 975) | No ISO equivalent | DIN 976-1 remains current. | Open |
The four wrench sizes that change
The most common difference between DIN and ISO hex fasteners is the width across flats at four sizes. It applies to hex bolts and hex nuts, so check your tools and packing.
| Size | DIN wrench size (mm) | ISO wrench size (mm) |
|---|---|---|
| M10 | 17 | 16 |
| M12 | 19 | 18 |
| M14 | 22 | 21 |
| M22 | 32 | 34 |
How to use an equivalent in an RFQ
- State the standard on your drawing first, for example DIN 933.
- Say whether the ISO equivalent is acceptable, for example ISO 4017 accepted.
- Confirm the wrench size for M10, M12, M14 and M22.
- State the property class, finish and any certificate separately. The standard number alone does not set them.
Frequently asked questions
What is the ISO equivalent of DIN 933?
ISO 4017. The wrench size differs at M10, M12, M14 and M22, so check these sizes before you substitute.
What is the ISO equivalent of DIN 931?
ISO 4014. The wrench size differs at M10, M12, M14 and M22.
What is the ISO equivalent of DIN 934?
ISO 4032 for coarse thread and ISO 8673 for fine thread. ISO nuts are taller at most sizes, and four wrench sizes change.
What is the ISO equivalent of DIN 912?
ISO 4762 for coarse thread and ISO 12474 for fine thread. Key dimensions match.
What is the ISO equivalent of DIN 125?
ISO 7089 for DIN 125-A and ISO 7090 for DIN 125-B. Key dimensions match, but hardness changes from 140 HV to 200 HV.
Are DIN and ISO fasteners interchangeable?
Often, but not always. Wrench size, nut height and hardness can differ, so check the change note and your drawing.