963

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 — deciding between them is yours, not ours.

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 |

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

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) |

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 |

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

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