# 963 — Fastener standard equivalences: DIN to ISO / EN crossover For 963, fastener description is Slotted countersunk (flat) head screws (Countersunk heads according to ISO); iso equivalent is 2009; interchangeability is Nominal size changed; head dimension changed; thread length changed; strength 8.8 cancelled; modification notes is Nominal size changed; head dimension changed; thread length changed; strength 8.8 cancelled, verified against its source on 2026-08-12. - **DIN standard:** 963 _(verified: appears in the quote below)_ - **Fastener description:** Slotted countersunk (flat) head screws (Countersunk heads according to ISO) _(verified: appears in the quote below)_ - **ISO equivalent:** 2009 _(verified: appears in the quote below)_ - **Interchangeability:** Nominal size changed; head dimension changed; thread length changed; strength 8.8 cancelled _(verified: appears in the quote below)_ - **Modification notes:** Nominal size changed; head dimension changed; thread length changed; strength 8.8 cancelled _(verified: appears in the quote below)_ ## What the source says > Slotted countersunk (flat) head screws (Countersunk heads according to ISO) | 963 | 2009 | | 2009 | 2009 | 1994-10 | Slotted countersunk flat head screws (common head style) – Product grade A | Nominal size changed; head dimension changed; thread length changed; strength 8.8 cancelled | ## 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 **Slotted countersunk (flat) head screws (Countersunk heads according to ISO)**, as of 2026-08-12. > Slotted countersunk (flat) head screws (Countersunk heads according to ISO) | 963 | 2009 | | 2009 | 2009 | 1994-10 | Slotted countersunk flat head screws (common head style) – Product grade A | Nominal size changed; head dimension changed; thread length changed; strength 8.8 cancelled | Source: https://fullerfasteners.com/tech/din-iso-en-crossover-chart/ monsterbolts.com says fastener description is **Countersink/head geometry differences.**, as of 2026-08-12. > DIN 963 | ISO 2009 | Check spec Source: https://monsterbolts.com/pages/common-din-numbers-for-metric-fasteners trfastenings.com says fastener description is **Slotted Countersunk Head Screws (with countersunk heads as specified in ISO 2009-1972)**, as of 2026-08-12. > DIN 963 | ISO 2009 | BS3692 | Slotted Countersunk Head Screws (with countersunk heads as specified in ISO 2009-1972) | Source: https://www.trfastenings.com/knowledge-base/engineering-data/fastener-standards ### Interchangeability fullerfasteners.com says interchangeability is **Nominal size changed; head dimension changed; thread length changed; strength 8.8 cancelled**, as of 2026-08-12. > Slotted countersunk (flat) head screws (Countersunk heads according to ISO) | 963 | 2009 | | 2009 | 2009 | 1994-10 | Slotted countersunk flat head screws (common head style) – Product grade A | Nominal size changed; head dimension changed; thread length changed; strength 8.8 cancelled | Source: https://fullerfasteners.com/tech/din-iso-en-crossover-chart/ monsterbolts.com says interchangeability is **Check spec**, as of 2026-08-12. > DIN 963 | ISO 2009 | 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 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/).