# DIN 939 — DIN / ISO / BS fastener equivalents and the sizes where they are not interchangeable

For DIN 939, part is Studs with a length of engagement equal to about 1,25 d, verified against its source on 2026-08-05.

- **DIN standard:** DIN 939 _(verified: appears in the quote below)_
- **Part:** Studs with a length of engagement equal to about 1,25 d _(verified: appears in the quote below)_

## What the source says

> DIN 939 | | | Studs with a length of engagement equal to about 1,25 d |

## Source

- https://www.trfastenings.com/knowledge-base/engineering-data/fastener-standards

Last verified: 2026-08-05. Review by: 2029-08-04.
Part of [DIN / ISO / BS fastener equivalents and the sizes where they are not interchangeable](https://referencesource.org/fastener-standard-interchangeability-exceptions/).