# 7991 — Fastener standard equivalences: DIN to ISO / EN crossover

For 7991, fastener description is Hexagon socket countersunk head screws; iso equivalent is 10462; en iso number is 10642, verified against its source on 2026-08-12.

- **DIN standard:** 7991 _(verified: appears in the quote below)_
- **Fastener description:** Hexagon socket countersunk head screws _(verified: appears in the quote below)_
- **ISO equivalent:** 10462 _(verified: appears in the quote below)_
- **EN ISO number:** 10642 _(verified: appears in the quote below)_
- **Interchangeability:** Check spec _(per monsterbolts.com, not stated by the source above)_

## What the source says

> 7991 | 10642 | | | 10462 | 2004-06 | Hexagon socket countersunk head screws |

## 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 **Hexagon socket countersunk head screws**, as of 2026-08-12.

> 7991 | 10642 | | | 10462 | 2004-06 | Hexagon socket countersunk head screws |

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

monsterbolts.com says fastener description is **Head angle/height differences exist.**, as of 2026-08-12.

> DIN 7991 | ISO 10642 | Check spec

Source: https://monsterbolts.com/pages/common-din-numbers-for-metric-fasteners

trfastenings.com says fastener description is **Hexagon Socket Countersunk Head Cap Screws**, as of 2026-08-12.

> DIN 7991 | ISO 10642 | BS4168 | Hexagon Socket Countersunk Head Cap Screws |

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


### ISO equivalent

fullerfasteners.com says iso equivalent is **10462**, as of 2026-08-12.

> 7991 | 10642 | | | 10462 | 2004-06 | Hexagon socket countersunk head screws |

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

monsterbolts.com says iso equivalent is **10642**, as of 2026-08-12.

> DIN 7991 | ISO 10642 | Check spec

Source: https://monsterbolts.com/pages/common-din-numbers-for-metric-fasteners

trfastenings.com says iso equivalent is **10642**, as of 2026-08-12.

> DIN 7991 | ISO 10642 | BS4168 | Hexagon Socket Countersunk Head Cap Screws |

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


## Source

- https://fullerfasteners.com/tech/din-iso-en-crossover-chart/
- https://monsterbolts.com/pages/common-din-numbers-for-metric-fasteners
- 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/).