The German standard DIN 934 specifies the metric coarse and fine pitch hexagon nuts ranging in size from M1 to M160. ISO 4032 is the internationally recognized equivalent and is interchangeable in most contexts of procurement and engineering.
934 is the standard "general purpose" hex nut in the DIN nut family. It is used in conjunction with DIN 985 (nyloc), DIN 6923 (flange nuts) and DIN 439 (thin hex nuts). The most common datasheet and BOM line items when it comes to standard pressure, structural, and mechanical bolt applications will refer to DIN 934.
Key Dimension Parameters: Width Across Flats and Nut Height
There are two dimensions that determine fit and function in practice:
- Width across flats (s): A width across the flats (s) is the distance between parallel flats. This is what a spanner or socket fits into. If a is incorrect for a particular bolt size, either the tooling will not engage or the nut will not fit around the available clearance around the joint.
- Nut height (m): The width of the nut. The more the thread is engaged the more the height will be. Pressure bolt and structural connection nuts cannot be below the specified height. A common site error, and a stress concentration risk, is using a smaller nut to fit into a confined area.
The pitch of threads used in the standard bolting series for M8 to M24 is coarse. Unless otherwise specified on the drawing, coarse pitch is the default; fine pitch applies in certain applications.
DIN 934 Hex Nut Dimensions
| Size | Pitch (mm) | Width Across Flats s (mm) | Nut Height m Min (mm) | Nut Height m Max (mm) |
|---|---|---|---|---|
| M8 | 1.25 | 13 | 6.14 | 6.5 |
| M10 | 1.50 | 17 | 7.64 | 8.0 |
| M12 | 1.75 | 19 | 9.64 | 10.0 |
| M16 | 2.00 | 24 | 12.3 | 13.0 |
| M20 | 2.50 | 30 | 14.9 | 16.0 |
| M24 | 3.00 | 36 | 17.7 | 19.0 |
Product grade A applies to sizes up to M16, product grade B to M16 and above. Grade A carries tighter tolerances on the bearing face and hole dimensions. If you are ordering M16 nuts specifically, confirm which product grade is required. Both grades exist in M16 and suppliers will not always flag the difference unprompted.
For the full dimension table covering M1 to M160 in all pitches, visit Unifit's DIN 934 dimensions page
DIN 934 Weight Chart M8 to M24
| Size | Weight (kg per 1000 pcs) |
|---|---|
| M8 | 5.20 |
| M10 | 11.6 |
| M12 | 17.3 |
| M16 | 33.3 |
| M20 | 64.4 |
| M24 | 110 |
Why Weight Matters for Bulk Orders
Hex nut weight is easy to overlook at the inquiry stage. By the time the freight quote arrives, it matters a lot.
A 1000-piece order of M24 nuts already runs to 110 kg. Across a multi-size consignment covering M12 through M24, the total weight determines which freight tier you fall into. Getting those figures wrong at the enquiry stage means the freight quote and the actual bill will not match.
For container load planning on larger orders, 10,000 pieces of M20 or M24 for example, weight per carton and per pallet needs to match the logistics team's input. The weight chart is also a useful cross-check on supplier quotes. If a competitor's quote implies a significantly different weight for the same quantity and size, that is worth querying before you place the order.
Property Classes and Material Options
DIN 934 property classes for nuts are not numbered the same way as bolt grades. Engineers sourcing both in the same order need to keep that distinction clear.
Steel Nut Property Classes
- Class 6: the baseline grade, available across the full range to M39. For sizes M1 to M2.5, class 6 is the only option.
- Class 8: suitable for higher-load structural and mechanical applications, commonly paired with Grade 8.8 bolts.
- Class 10: for high-tensile bolting, typically used alongside Grade 10.9 bolts in demanding mechanical assemblies.
Stainless Steel Options
- A2-70 (304 stainless): the standard choice for corrosion resistance in general process, food-grade, and outdoor structural applications. Available to M39, above that by agreement.
- A4-70 (316 stainless): for chloride-exposed environments including marine, chemical processing, and coastal installations. Same size range as A2.
Above M39, property class availability for both steel and stainless is by agreement with the manufacturer, so confirm early in the sourcing process if you are dealing with large diameter nuts.
Above M39, property class availability for both steel and stainless is by agreement with the manufacturer, so confirm early in the sourcing process if you are dealing with large diameter nuts.
Sourcing DIN 934 Hex Nuts from Unifit
For complete dimension and weight specifications across the full M1-M160 range, including all pitch variations and property classes, Unifit Metalloys maintains detailed charts covering every size and grade. Their broader catalog also covers the full spectrum of DIN-standard fasteners, with multiple grades, finishes, and stock quantities available to suit different project needs.
Unifit Metalloys supplies DIN 934 hex nuts across property classes 6, 8, and 10, and stainless A2/A4 grades, with EN 10204 3.1 mill certification and export capability to the Middle East, Europe, and Southeast Asia.
Get in touch with Unifit Metalloys today to request the full DIN 934 dimension chart or discuss your specific fastener requirements.
Frequently Asked Questions
Yes. DIN 934 and ISO 4032 are dimensionally and mechanically aligned standards for hexagon nuts, and most mills and suppliers treat them as interchangeable for procurement purposes. It's still good practice to confirm the exact standard on your drawing or BOM, since some buyers specify one over the other for traceability reasons.
Both grades exist at M16, so the size alone won't tell you which one you need. Grade A carries tighter tolerances on the bearing face and hole, and is typically required for higher-precision or critical-service joints; Grade B is the more economical default for general-purpose use. Confirm the required grade against your project drawing before placing the order.
As a rule of thumb, nut property class should match or exceed the bolt's strength grade so the nut doesn't become the weak link in the joint - Class 8 nuts for Grade 8.8 bolts, Class 10 for Grade 10.9. Always check the joint design or relevant bolting standard rather than assuming, since some assemblies call for an over-matched nut for added safety margin.
Yes - A2-70 (304) and A4-70 (316) nuts are typically supplied with EN 10204 3.1 mill test certificates confirming chemical composition and mechanical properties, which most buyers need for project traceability. MOQ and lead time vary by size and quantity, so it's worth confirming both at enquiry stage, especially for large or mixed-size orders.