DIN 985 specifies thin hexagon nuts with a nylon insert — prevailing torque lock nuts that resist loosening from vibration. The current standard is ISO 10511; the legacy German designation is DIN 985, and in our compiled data all 22 sizes from M3 to M48 match between the two. This page gives the complete dimension table with heights, across-flats, across-corners and theoretical weight per 1,000 pieces.
| Parameter (mm) | M3 | M4 | M5 | M6 | M7 | M8 | M10 | M12 | M14 | M16 | M18 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| P — pitch (mm) | 0.5 | 0.7 | 0.8 | 1 | 1 | 1.25 | 1.5 | 1.75 | 2 | 2 | 2.5 |
| da — max | 3.45 | 4.6 | 5.75 | 6.75 | 7.75 | 8.75 | 10.8 | 13 | 15.1 | 17.3 | 19.5 |
| da — min | 3 | 4 | 5 | 6 | 7 | 8 | 10 | 12 | 14 | 16 | 18 |
| dw — min | 4.6 | 5.9 | 6.9 | 8.9 | 9.6 | 11.6 | 15.6 | 17.4 | 20.5 | 22.5 | 24.9 |
| e (across corners) — min | 6.01 | 7.66 | 8.79 | 11.05 | 12.12 | 14.38 | 18.9 | 21.1 | 24.49 | 26.75 | 29.56 |
| h — height max | 4 | 5 | 5 | 6 | 7.5 | 8 | 10 | 12 | 14 | 16 | 18.5 |
| h — height min | 3.7 | 4.7 | 4.7 | 5.7 | 7.14 | 7.64 | 9.64 | 11.57 | 13.3 | 15.3 | 17.66 |
| m — min | 2.4 | 2.9 | 3.2 | 4 | 4.7 | 5.5 | 6.5 | 8 | 9.5 | 10.5 | 13 |
| m′ — min | 1.65 | 2.2 | 2.75 | 3.3 | 3.85 | 4.4 | 5.5 | 6.6 | 7.7 | 8.8 | 9.9 |
| s (across flats) — nominal = max | 5.5 | 7 | 8 | 10 | 11 | 13 | 17 | 19 | 22 | 24 | 27 |
| s — min | 5.32 | 6.78 | 7.78 | 9.78 | 10.73 | 12.73 | 16.73 | 18.67 | 21.67 | 23.67 | 26.16 |
| Weight — kg / 1,000 pcs | 0.5 | 1 | 1.4 | 2.4 | 3 | 5.1 | 10.6 | 17.2 | 26 | 34 | 45 |
Source: DIN 985 / ISO 10511 compiled table (see Sources). Dimensions in millimetres; weight is a theoretical estimate per 1,000 pieces.
| Parameter (mm) | M20 | M22 | M24 | M27 | M30 | M33 | M36 | M39 | M42 | M45 | M48 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| P — pitch (mm) | 2.5 | 2.5 | 3 | 3 | 3.5 | 3.5 | 4 | 4 | 4.5 | 4.5 | 5 |
| da — max | 21.6 | 23.7 | 25.9 | 29.1 | 32.4 | 35.6 | 38.9 | 42.1 | 45.4 | 48.6 | 51.8 |
| da — min | 20 | 22 | 24 | 27 | 30 | 33 | 36 | 39 | 42 | 45 | 48 |
| dw — min | 27.7 | 29.5 | 33.2 | 38 | 42.7 | 46.6 | 51.1 | 55.9 | 60.6 | 64.7 | 69.4 |
| e (across corners) — min | 32.95 | 35.03 | 39.55 | 45.2 | 50.85 | 55.37 | 60.79 | 66.44 | 72.09 | 76.95 | 82.6 |
| h — height max | 20 | 22 | 24 | 27 | 30 | 33 | 36 | 39 | 42 | 45 | 48 |
| h — height min | 18.7 | 20.7 | 22.7 | 25.7 | 28.7 | 31.4 | 34.4 | 37.4 | 40.4 | 43.4 | 46.4 |
| m — min | 14 | 15 | 15 | 17 | 19 | 22 | 25 | 27 | 29 | 32 | 36 |
| m′ — min | 11 | 12.2 | 13.2 | 14.8 | 16.5 | 18.2 | 19.8 | 21.5 | 23.1 | 24.8 | 26.5 |
| s (across flats) — nominal = max | 30 | 32 | 36 | 41 | 46 | 50 | 55 | 60 | 65 | 70 | 75 |
| s — min | 29.16 | 31 | 35 | 40 | 45 | 46 | 53.8 | 58.8 | 63.8 | 68.1 | 73.1 |
| Weight — kg / 1,000 pcs | 65 | 75 | 100 | 162 | 212 | 317 | 415 | 499 | 628 | 771 | 998 |
Source: DIN 985 / ISO 10511 compiled table (see Sources). Dimensions in millimetres; weight is a theoretical estimate per 1,000 pieces.
The standard also covers fine-pitch versions of some sizes; available combinations include: M8x1, M10x1, M10x1,25, M12x1,5, M12x1,25, M14x1,5, M16x1,5, M18x2, M18x1,5, M20x2, M20x1,5, M22x2, M22x1,5, M33x2, M36x3, M39x3, M42x3, M45x3, M48x3. State the pitch when ordering — the table above shows the coarse pitch P.
The nylon insert grips the bolt thread and creates a prevailing torque, so the nut does not back off under vibration. The thin (DIN 985 / ISO 10511) version is used where nut height is limited; where more thread engagement is needed, use the standard-height DIN 982 / ISO 7040 type. The insert is a non-metallic (nylon) ring — check the service temperature with us for hot applications.
Supplied in carbon steel and stainless steel (A2 / A4) with zinc plating, hot-dip galvanizing, zinc-nickel or dacromet finishes. The standard covers metric sizes and a range of property classes; confirm the class and coating on the drawing or order — see mechanical properties and surface treatment.
State the standard (DIN 985 or the equivalent), size and pitch, material / grade, finish and quantity. For hot applications, tell us the service temperature so the insert material can be confirmed.
DIN 985 is the thin hexagon nut with a nylon insert (non-metallic prevailing torque insert). The nylon ring grips the thread and resists loosening from vibration; the nut is thinner than the standard-height DIN 982 type, so it is used where space or weight is limited.
Dimensionally yes — in our compiled data all 22 sizes from M3 to M48 match ISO 10511. DIN 985 is the legacy German designation; ISO 10511 is the current international standard for thin prevailing torque nuts with non-metallic insert.
DIN 985 is the thin version; DIN 982 is the standard-height version (ISO 7040). Use DIN 985 where height is restricted, DIN 982 where more thread engagement is needed.
DIN 985 M10: width across flats s = 17 mm, height h = 10 mm, across-corners e = 18.9 mm, about 10.6 kg per 1,000 pieces.
h is the overall nut height, m the minimum nut thickness at the bearing face, m′ the minimum thickness at the top face, and s the width across flats.
Yes — fine pitch threads are available in the sizes listed in the table notes (for example M10x1 and M10x1.25, M12x1.5 and M12x1.25). State the pitch on the order.
The last row gives the theoretical weight per 1,000 pieces — e.g. M10 about 10.6 kg, M16 about 34 kg, M30 about 212 kg per 1,000.
Yes — A2 / A4 stainless steel and zinc plated, hot-dip galvanized, zinc-nickel or dacromet finishes. The nylon insert has a service-temperature limit, so tell us the application temperature.
Dimensions and weights: DIN 985 / ISO 10511 compiled table (source: fasteners.eu, retrieved 2026-10-30); DIN 985 and ISO 10511 verified size-by-size identical (22/22). Weight values are theoretical per 1,000 pieces. Page last reviewed: 2026-10-30.