← AskMachinist · Guides · Calculator · 🔎 Search

Small Series Washer Dimensions (ISO 7092 / DIN 433, M1.6 to M36)

Guide · Updated October 28, 2026

ISO 7092 (formerly DIN 433) covers small series flat washers, M1.6 to M36, sized for cheese head and socket head cap screws where a standard ISO 7089 washer would overhang the head. The values below agree across the ISO 7092:2000 preview (iTeh), the JC Fasteners ISO 7092 data sheet, fasten.it DIN EN ISO 7092 and Engineering Hardware; fasteners.eu was checked but has typos at M2.5, M24 and M36, so it was not counted. Conflicting cells are shown as a dash. Check your supplier for critical work.

Step by step

1. Pick the size: Choose by thread, M1.6 to M36.
2. Read the hole: Hole d1 min and max.
3. Read the OD: d2 max and min; small series OD is close to the head of a socket head cap screw or cheese head screw.
4. Read the thickness: h nominal, max and min.
5. Order it: Designate as Washer ISO 7092 - 8 - 200 HV (or 300 HV for 10.9 socket screws).

ISO 7092 / DIN 433 small series washer dimensions (mm)

Columns: thread, hole d1 min and max, OD d2 max and min, thickness h nominal, max and min.

• Thread | d1 min | d1 max | d2 max | d2 min | h | h max | h min
• M1.6 | 1.70 | 1.84 | 3.5 | 3.2 | 0.3 | 0.35 | 0.25
• M2 | 2.20 | 2.34 | 4.5 | 4.2 | 0.3 | 0.35 | 0.25
• M2.5 | 2.70 | 2.84 | 5.0 | 4.7 | 0.5 | 0.55 | 0.45
• M3 | 3.20 | 3.38 | 6.0 | 5.7 | 0.5 | 0.55 | 0.45
• M3.5 | 3.70 | 3.88 | 7.0 | 6.64 | 0.5 | 0.55 | 0.45
• M4 | 4.30 | 4.48 | 8.0 | 7.64 | 0.5 | 0.55 | 0.45
• M5 | 5.30 | 5.48 | 9.0 | 8.64 | 1 | 1.1 | 0.9
• M6 | 6.40 | 6.62 | 11.0 | 10.57 | 1.6 | 1.8 | 1.4
• M8 | 8.40 | 8.62 | 15.0 | 14.57 | 1.6 | 1.8 | 1.4
• M10 | 10.50 | 10.77 | 18.0 | 17.57 | 1.6 | 1.8 | 1.4
• M12 | 13.00 | 13.27 | 20.0 | 19.48 | 2 | 2.2 | 1.8
• M14 | 15.00 | 15.27 | 24.0 | 23.48 | 2.5 | 2.7 | 2.3
• M16 | 17.00 | 17.27 | 28.0 | 27.48 | 2.5 | 2.7 | 2.3
• M18 | 19.00 | 19.33 | 30.0 | 29.48 | — | — | —
• M20 | 21.00 | 21.33 | 34.0 | 33.38 | 3 | 3.3 | 2.7
• M22 | 23.00 | 23.33 | 37.0 | 36.38 | 3 | 3.3 | 2.7
• M24 | 25.00 | 25.33 | 39.0 | 38.38 | 4 | 4.3 | 3.7
• M27 | 28 | — | 44 | — | 4 | — | —
• M30 | 31.00 | 31.39 | 50.0 | 49.38 | 4 | 4.3 | 3.7
• M33 | 34 | — | 56 | — | — | — | —
• M36 | 37.00 | 37.62 | 60.0 | 58.8 | 5 | 5.6 | 4.4

How it compares with other washers

At M8 the hole is 8.4 mm in each series; the OD is 15 mm for ISO 7092, 16 mm for ISO 7089 and ISO 7090, and 24 mm for DIN 9021. Use ISO 7092 where the washer must sit inside a socket head counterbore.

Worked example: M6 socket head cap screw

An M6 ISO 7092 washer has a 6.40 to 6.62 mm hole, 10.57 to 11 mm OD and is 1.4 to 1.8 mm thick, so it sits under a 10 mm socket head with very little overhang.

Common problems

• Washer too big for the counterbore: switch from ISO 7089 to ISO 7092.
• Washer dents under a 10.9 screw: use 300 HV.
• Soft material or large clearance hole: the small OD may not spread the load; check suitability.

FAQ

What is ISO 7092?

The small series plain washer, product grade A, for cheese head, socket head cap and hexalobular socket screws. It replaced DIN 433.

ISO 7092 vs ISO 7089?

Same hole, smaller OD and often thinner: M8 is 15 mm OD x 1.6 in ISO 7092 versus 16 mm OD in ISO 7089.

200 HV or 300 HV?

200 HV for screws up to class 8.8 or stainless; 300 HV for socket head cap screws up to 10.9.

Why is the M18 thickness blank?

Sources disagree: the ISO 7092 preview lists 3 mm (3.3 / 2.7) while the JC Fasteners sheet, fasten.it and fasteners.eu list 2.5 mm.

Why are some M27 and M33 cells blank?

M33 thickness disagrees (5 mm in ISO 7092 and fasten.it, 4.3 / 3.7 max/min in JC Fasteners). M27 and M33 hole and OD tolerances appeared in only one source.

What was skipped?

Weights (sources disagree, e.g. M12 2.65 vs 2.85 kg per 1000), DIN 433 M1 to M1.4 sizes outside ISO 7092, M18 thickness and the M27/M33 cells noted above.

Related guides and calculators

• Flat washer size chart (SAE, USS, metric)
• Chamfered washer dimensions (DIN 125 B / ISO 7090)
• Large OD washer dimensions (DIN 9021)
• Heavy duty washer dimensions (DIN 7989)
• All free machinist calculators

General shop information only — follow your drawing, tool maker's data and your quality system.