# 939 — Fastener standard equivalences: DIN to ISO / EN crossover

For 939, fastener description is Studs with a length of engagement equal to about 1,25 d, verified against its source on 2026-08-12.

- **DIN standard:** 939 _(verified: appears in the quote below)_
- **Fastener description:** 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: 2026-08-12. Review by: 2028-08-11.
Part of [Fastener standard equivalences: DIN to ISO / EN crossover](https://referencesource.org/fastener-thread-standard-equivalence/).