558
For 558, fastener description is Hexagon screws, Thread Approximately to Head, Metric Thread, Type g; iso equivalent is 4018; interchangeability is Nominal size extended; width across flats according to DIN ISO 272 included; modification notes is Nominal size extended; width across flats according to DIN ISO 272 included, verified against its source on 2026-08-12.
- DIN standard
- 558 verified
- Fastener description
- Hexagon screws, Thread Approximately to Head, Metric Thread, Type g verified
- ISO equivalent
- 4018 verified
- Interchangeability
- Nominal size extended; width across flats according to DIN ISO 272 included verified
- Modification notes
- Nominal size extended; width across flats according to DIN ISO 272 included verified
What the source says
Hexagon screws, Thread Approximately to Head, Metric Thread, Type g | 558 | 4018 | 24018 | 4018 | 4018 | 2001-03 | Hexagon head screws – Product grade C | Nominal size extended; width across flats according to DIN ISO 272 included |
— fullerfasteners.com, retrieved 2026-08-12
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 Hexagon screws, Thread Approximately to Head, Metric Thread, Type g, as of 2026-08-12.
Hexagon screws, Thread Approximately to Head, Metric Thread, Type g | 558 | 4018 | 24018 | 4018 | 4018 | 2001-03 | Hexagon head screws – Product grade C | Nominal size extended; width across flats according to DIN ISO 272 included |
https://fullerfasteners.com/tech/din-iso-en-crossover-chart/
monsterbolts.com says fastener description is Alt coarse hex FT., as of 2026-08-12.
DIN 558 | ISO 4018 | Fully interchangeable
https://monsterbolts.com/pages/common-din-numbers-for-metric-fasteners
trfastenings.com says fastener description is Hexagon Head Screws, as of 2026-08-12.
DIN 558 | ISO 4018 | | Hexagon Head Screws |
https://www.trfastenings.com/knowledge-base/engineering-data/fastener-standards
Interchangeability
fullerfasteners.com says interchangeability is Nominal size extended; width across flats according to DIN ISO 272 included, as of 2026-08-12.
Hexagon screws, Thread Approximately to Head, Metric Thread, Type g | 558 | 4018 | 24018 | 4018 | 4018 | 2001-03 | Hexagon head screws – Product grade C | Nominal size extended; width across flats according to DIN ISO 272 included |
https://fullerfasteners.com/tech/din-iso-en-crossover-chart/
monsterbolts.com says interchangeability is Fully interchangeable, as of 2026-08-12.
DIN 558 | ISO 4018 | Fully interchangeable
https://monsterbolts.com/pages/common-din-numbers-for-metric-fasteners
Sources
- fullerfasteners.comhttps://fullerfasteners.com/tech/din-iso-en-crossover-chart/
- monsterbolts.comhttps://monsterbolts.com/pages/common-din-numbers-for-metric-fasteners
- trfastenings.comhttps://www.trfastenings.com/knowledge-base/engineering-data/fastener-standards