# 7977 — Fastener standard equivalences: DIN to ISO / EN crossover

For 7977, fastener description is Unhardened taper pins with external thread; iso equivalent is 8737; en iso number is 28737; interchangeability is Technical delivery conditions partially changed; modification notes is Technical delivery conditions partially changed, verified against its source on 2026-08-12.

- **DIN standard:** 7977 _(verified: appears in the quote below)_
- **Fastener description:** Unhardened taper pins with external thread _(verified: appears in the quote below)_
- **ISO equivalent:** 8737 _(verified: appears in the quote below)_
- **EN ISO number:** 28737 _(verified: appears in the quote below)_
- **Interchangeability:** Technical delivery conditions partially changed _(verified: appears in the quote below)_
- **Modification notes:** Technical delivery conditions partially changed _(verified: appears in the quote below)_

## What the source says

> 7977 | | 28737 | | 8737 | 1992-10 | Unhardened taper pins with external thread | Technical delivery conditions partially changed |

## Sources disagree

More than one authority states this, and they do not state the same
thing. Both are reproduced with the source each came from.

### Fastener description

fullerfasteners.com says fastener description is **Unhardened taper pins with external thread**, as of 2026-08-12.

> 7977 | | 28737 | | 8737 | 1992-10 | Unhardened taper pins with external thread | Technical delivery conditions partially changed |

Source: https://fullerfasteners.com/tech/din-iso-en-crossover-chart/

trfastenings.com says fastener description is **Taper Pins with thread ends and constant point lengths**, as of 2026-08-12.

> DIN 7977 | ISO 8737 | | Taper Pins with thread ends and constant point lengths |

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


## Source

- https://fullerfasteners.com/tech/din-iso-en-crossover-chart/
- 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/).