# 6926 — Fastener standard equivalences: DIN to ISO / EN crossover

For 6926, fastener description is Prevailing torque type hexagon nuts with flange (with non-metallic insert), with metric fine pitch thread; iso equivalent is 12125; en iso number is 1666; interchangeability is Width across flat M10 changed; modification notes is Width across flat M10 changed, verified against its source on 2026-08-12.

- **DIN standard:** 6926 _(verified: appears in the quote below)_
- **Fastener description:** Prevailing torque type hexagon nuts with flange (with non-metallic insert), with metric fine pitch thread _(verified: appears in the quote below)_
- **ISO equivalent:** 12125 _(verified: appears in the quote below)_
- **EN ISO number:** 1666 _(verified: appears in the quote below)_
- **Interchangeability:** Width across flat M10 changed _(verified: appears in the quote below)_
- **Modification notes:** Width across flat M10 changed _(verified: appears in the quote below)_

## What the source says

> 6926 | | 1666 | | 12125 | 1998-02 | Prevailing torque type hexagon nuts with flange (with non-metallic insert), with metric fine pitch thread | Width across flat M10 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 **Prevailing torque type hexagon nuts with flange (with non-metallic insert), with metric fine pitch thread**, as of 2026-08-12.

> 6926 | | 1666 | | 12125 | 1998-02 | Prevailing torque type hexagon nuts with flange (with non-metallic insert), with metric fine pitch thread | Width across flat M10 changed |

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

monsterbolts.com says fastener description is **Deformation style/serrations differ.**, as of 2026-08-12.

> DIN 6926 | DIN EN 1663, 1666 | Check spec

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

trfastenings.com says fastener description is **Prevailing torque type Hexagon Nuts with flange and with non-metallic insert**, as of 2026-08-12.

> DIN 6926 | ISO 7043 | | Prevailing torque type Hexagon Nuts with flange and with non-metallic insert | DIN 6926 | ISO 12125 |

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

trfastenings.com says fastener description is **Prevailing torque type Hexagon Nuts with flange and with non-metallic insert**, as of 2026-08-12.

> DIN 6926 | ISO 7043 | | Prevailing torque type Hexagon Nuts with flange and with non-metallic insert |

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


### ISO equivalent

fullerfasteners.com says iso equivalent is **12125**, as of 2026-08-12.

> 6926 | | 1666 | | 12125 | 1998-02 | Prevailing torque type hexagon nuts with flange (with non-metallic insert), with metric fine pitch thread | Width across flat M10 changed |

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

monsterbolts.com says iso equivalent is **1663, 1666**, as of 2026-08-12.

> DIN 6926 | DIN EN 1663, 1666 | Check spec

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

trfastenings.com says iso equivalent is **12125**, as of 2026-08-12.

> DIN 6926 | ISO 7043 | | Prevailing torque type Hexagon Nuts with flange and with non-metallic insert | DIN 6926 | ISO 12125 |

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

trfastenings.com says iso equivalent is **7043**, as of 2026-08-12.

> DIN 6926 | ISO 7043 | | Prevailing torque type Hexagon Nuts with flange and with non-metallic insert |

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


### Interchangeability

fullerfasteners.com says interchangeability is **Width across flat M10 changed**, as of 2026-08-12.

> 6926 | | 1666 | | 12125 | 1998-02 | Prevailing torque type hexagon nuts with flange (with non-metallic insert), with metric fine pitch thread | Width across flat M10 changed |

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

monsterbolts.com says interchangeability is **Check spec**, as of 2026-08-12.

> DIN 6926 | DIN EN 1663, 1666 | Check spec

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


## 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
- 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/).