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Extra Large Washer Dimensions (ISO 7094, M5 to M36)
Guide · Updated October 28, 2026
ISO 7094 covers extra large series plain washers, product grade C, 100 HV, M5 to M36. This chart shows the preferred sizes. Values agree across the ISO 7094:2000 published table, fasteners.eu and globalfastener.
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Step by step
- Find the bolt size: Pick the row for your thread, M5 to M36.
- Check the hole: d1 is a clearance hole, e.g. 11 to 11.43 mm for M10.
- Check the footprint: d2 is the outside diameter; make sure it fits the face, e.g. 34 mm for M10.
- Check the stack: Use h max when working out bolt length.
ISO 7094 extra large washer dimensions (mm)
Columns: thread size, hole d1 min (nom.) and max, outside diameter d2 max (nom.) and min, thickness h nom., max and min.
- Size | d1 min | d1 max | d2 max | d2 min | h | h max | h min
- M5 | 5.5 | 5.8 | 18 | 16.9 | 2 | 2.3 | 1.7
- M6 | 6.6 | 6.96 | 22 | 20.7 | 2 | 2.3 | 1.7
- M8 | 9 | 9.36 | 28 | 26.7 | 3 | 3.6 | 2.4
- M10 | 11 | 11.43 | 34 | 32.4 | 3 | 3.6 | 2.4
- M12 | 13.5 | 13.93 | 44 | 42.4 | 4 | 4.6 | 3.4
- M16 | 17.5 | 18.2 | 56 | 54.1 | 5 | 6 | 4
- M20 | 22 | 22.84 | 72 | 70.1 | 6 | 7 | 5
- M24 | 26 | 26.84 | 85 | 82.8 | 6 | 7 | 5
- M30 | 33 | 34 | 105 | 102.8 | 6 | 7 | 5
- M36 | 39 | 40 | 125 | 122.5 | 8 | 9.2 | 6.8
Worked example: M12 washer
An M12 ISO 7094 washer has a 13.5 to 13.93 mm hole, a 42.4 to 44 mm outside diameter and is 3.4 to 4.6 mm thick. Allow 4.6 mm per washer when sizing the bolt.
Common problems
- Will not fit the face: d2 is large; check the space around the bolt.
- Bolt too short: thick washers add length; use h max.
- Wrong series: DIN 9021 / ISO 7093 is smaller; order by standard.
FAQ
ISO 7094 vs DIN 9021 / ISO 7093?
ISO 7094 is a larger outside diameter and thicker: M10 is 34 x 3 mm vs 30 x 2.5 mm for DIN 9021.
What is ISO 7094 for?
The standard says these washers suit grade C hex bolts and nuts in timber structures.
What hardness are they?
Steel in the 100 HV hardness class, product grade C.
Why no M14, M18 or M22?
Only preferred sizes are listed; sources disagree on some non-preferred tolerances.
Related guides and calculators
- Timber washers (DIN 1052)
- Large washers (DIN 9021)
- Thick washers (DIN 7349)
- Flat washer size chart
- All free machinist calculators
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