Wrench Size
Wrench Size (SW:Schlüsselweite, Wrench Width, Width across flats)
Possible wrenches that can be used:
| Thread Size (Nominal Diameter) |
SW Width (Width Across Flats) |
Head Height (k) |
|---|---|---|
| M5 | 8 | 3.5 |
| M6 | 10 | 4 |
| M8 | 13 | 5.3 |
| M10 | 17 | 6.4 |
| M12 | 19 | 7.5 |
| M14 | 22 | 8.8 |
| M16 | 24 | 10 |
| M18 | 27 | 11.5 |
| M20 | 30 | 12.5 |
| M22 | 32 | 14 |
| M24 | 36 | 15 |
| M27 | 41 | 17 |
| M30 | 46 | 18.7 |
| M33 | 50 | 21 |
| M36 | 55 | 22.5 |
Sample Shafts:
Shaft and Hexagon Diagram:
ISO 10102:2018 Assembly tools for screws and nuts - Double-headed open-ended engineers' wrenches.
ISO 3318:2016 Assembly tools for screws and nuts - Open-ended wrenches, box wrenches and combination wrenches - Maximum widths of heads.
ISO 1085:2016 Assembly tools for screws and nuts - Double-ended wrenches - Size pairing.
ISO 691:2005 Assembly Tools for Screws and Nuts - Wrench and Socket Openings - Tolerances for General Use
DIN 3110:1987 Engineers wrenches, double head, open end, with unequal jaw widths; test torques series c.
DIN 475-2:1982 Wrench and socket openings.