Hex Nuts with Collar, 1.5d Height manufactured to DIN 6331 are dimensioned by the size table reproduced on this page. The standard fixes geometry and tolerances only; material and property class are assigned by separate documents, and surface finish by separate finish standards.
DIN 6331 — Scope
DIN 6331 is "Hexagon nuts with collar, height 1.5 d".
Material, property class, surface finish and packaging are governed by separate documents — ISO 898-1 and ISO 898-2 for mechanical property classes, ISO 4042 for electroplated finishes.
Tolerance & Product Grades
DIN 6331 does not divide hex nuts with collar, 1.5d height into product grades. Tolerances are given as limits on the individual dimensions in the table.
Where a general-tolerance class is cited on the drawing instead, it applies to the dimensions not otherwise toleranced.
Dimensions Specified by DIN 6331
| Size | Pitch P (mm) | a (mm) | d1 (mm) | damin (mm) | damax (mm) | Nut height m (mm) | Width across flats s (mm) | Note | Reference standard |
|---|---|---|---|---|---|---|---|---|---|
| M6 | 1.0 | 3 | 14 | 6 | 6.75 | 9 | 10 | DIN 6331 | |
| M8 | 1.25 | 3 | 5 | 18 | 8 | 8.75 | 12 | 13 | DIN 6331 |
| M10 | 1.5 | 4 | 22 | 10 | 10.8 | 15 | 16 | DIN 6331 | |
| M12 | 1.75 | 4 | 25 | 12 | 13 | 18 | 18 | DIN 6331 | |
| M16 | 2.0 | 5 | 31 | 16 | 17.3 | 24 | 24 | DIN 6331 | |
| M20 | 2.5 | 6 | 37 | 20 | 21.6 | 30 | 30 | DIN 6331 | |
| M24 | 3.0 | 6 | 45 | 24 | 25.9 | 36 | 36 | DIN 6331 | |
| M27 | 3.0 | 7 | 50 | 27 | 29.1 | 40 | 41 | DIN 6331 | |
| M30 | 3.5 | 8 | 58 | 30 | 32.4 | 45 | 46 | DIN 6331 | |
| M36 | 4.0 | 10 | 68 | 36 | 38.9 | 54 | 55 | DIN 6331 | |
| M42 | 4.5 | 12 | 80 | 42 | 45.4 | 63 | 65 | DIN 6331 | |
| M48 | 5.0 | 14 | 92 | 48 | 51.8 | 72 | 75 | DIN 6331 |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Hex Nuts with Collar, 1.5d Height page.
Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
Companion Standards
DIN 6331 controls only the geometry of hex nuts with collar, 1.5d height. The mechanical strength is set by ISO 898-1 (bolts, screws and studs) or ISO 898-2 (nuts); the surface finish is governed by separate finish standards such as ISO 4042 for electroplating. For corrosion testing, the relevant document is ISO 9227 (neutral salt spray).
Custom manufacturing · Made to drawing
Need a nut to this standard in a non-standard size?
Parts built to DIN 6331 are already in the catalog, so a special is usually a variation on existing tooling rather than a new design — which is what keeps the cost down. Made by cold heading or tapping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
