DIN934 Hex Nut | SS316 ISO4032 Marine Grade Hexagon Nut
DIN934 Hex Nut | SS316 ISO4032 Marine Grade Hexagon Nut
Standards: DIN 934 / ISO 4032 / EN 24032 | Size: M1.6 - M64 | Property Classes: 5 / 6 / 8 / 10 / A2-70 / A4-80
Surface: Plain / Zinc Plated / Hot-Dip Galvanized / Black Oxide / Dacromet
DIN934 hexagon nut (superseded by ISO 4032) is the most widely used metric hex nut in marine engineering and general industrial assembly. The Style 1 full-height configuration with 6H thread tolerance ensures consistent clamp load and repeatable torque values across all mating bolt property classes. The nut height, approximately 0.8 times the nominal diameter, provides full thread engagement that distributes tensile load evenly across all engaged thread turns, preventing thread stripping under shock and cyclic loading common in shipboard service.
Marine Applications
- Engine Room: Pump motor mounting plates, heat exchanger saddle brackets, compressor isolation mounts, electrical panel frames, auxiliary machinery foundations
- Piping Flanges: Seawater cooling line flanges, ballast pipe connections, fuel oil transfer fittings, freshwater system joints
- Deck Equipment: Cleat backing plates, davit mounting brackets, winch base fasteners, handrail post anchors
- Hull Structure: Frame-to-plate connections, bracket fastening, non-watertight access panel assemblies
Material and Property Class Matching
Per ISO 898-2, the nut property class must match or exceed the paired bolt class to ensure the joint fails at the bolt rather than the nut. Mismatched pairings (e.g., class 5 nut on a 10.9 bolt) reduce joint strength to the weaker component.
| Bolt Class | Recommended Nut Class | Notes |
|---|---|---|
| 4.8 / 5.8 | Class 5 | Low-strength carbon steel, general purpose |
| 8.8 | Class 8 | Most common pairing, zinc plated or HDG |
| 10.9 | Class 10 | High-strength alloy steel, structural joints |
| 12.9 | Class 12 | Specialty; often requires Style 2 high nut |
| A2-70 (SS304) | A2-70 nut | Match alloy and grade |
| A4-80 (SS316) | A4-80 nut | Marine saltwater environment, 2-3% Mo content |
DIN 934 vs ISO 4032 Dimensional Differences
DIN 934 has been formally withdrawn in favour of ISO 4032. Most sizes are dimensionally identical, but four diameters differ in width across flats. Confirm the standard specified on your drawing before ordering.
| Size | DIN 934 WAF (mm) | ISO 4032 WAF (mm) | Difference |
|---|---|---|---|
| M10 | 17 | 16 | -1 mm |
| M12 | 19 | 18 | -1 mm |
| M14 | 22 | 21 | -1 mm |
| M22 | 32 | 34 | +2 mm |
All other sizes from M1.6 to M64 share identical width across flats. ISO 4032 nuts are also approximately 0.2-0.7 mm taller than DIN 934 from M5 upward due to increased proof load requirements in ISO 898-2:2022.
SS316 A4-80 Marine Grade Hex Nut
The A4-80 designation per ISO 3506-2 identifies austenitic stainless steel grade 316 with minimum 800 MPa tensile strength. The 2-3% molybdenum content in SS316 forms a protective passive oxide layer that resists chloride pitting corrosion in saltwater atmospheres, making A4-80 hex nuts the standard choice for seawater line flanges, below-waterline fittings, and topside deck hardware where standard 304 grade (A2-70) would suffer premature corrosion.
| Property | A2-70 (SS304) | A4-80 (SS316) |
|---|---|---|
| Tensile Strength | 700 MPa | 800 MPa |
| Molybdenum Content | None | 2-3% |
| Chloride Pitting Resistance | Good (freshwater, indoor) | Excellent (saltwater, chemical) |
| Marine Application | Topside, dry compartments | Seawater systems, below waterline |
Key Dimensions (Selected Sizes)
| Thread | Pitch P (mm) | Width Across Flats s (mm) | Height m (mm) | Across Corners e min (mm) |
|---|---|---|---|---|
| M6 | 1.0 | 10 | 5.2 | 11.05 |
| M8 | 1.25 | 13 | 6.8 | 14.38 |
| M10 | 1.5 | 16 | 8.4 | 18.90 |
| M12 | 1.75 | 18 | 10.8 | 21.10 |
| M16 | 2.0 | 24 | 14.8 | 26.75 |
| M20 | 2.5 | 30 | 18.0 | 32.95 |
| M24 | 3.0 | 36 | 21.5 | 39.55 |
| M30 | 3.5 | 46 | 25.6 | 50.85 |
| M36 | 4.0 | 55 | 31.0 | 60.79 |
Dimensions per ISO 4032. Full dimension table covers M1.6 through M64 in both coarse and fine pitch. Fine pitch hex nuts per ISO 8673 available on request.
Specifications
| Product Name | DIN934 Hex Nut / ISO 4032 Hexagon Nut |
| Standard | DIN 934 / ISO 4032 / EN 24032 |
| Type | Style 1 Full Hex Nut (Regular Height, h approx. 0.8d) |
| Size Range | M1.6 - M64 |
| Thread Class | 6H (Coarse per ISO 965-1); Fine Pitch ISO 8673 Available |
| Material / Grade | Carbon Steel Class 5 / 6 / 8 / 10 / 12; SS304 A2-70; SS316 A4-80; 316L |
| Surface Finish | Plain / Zinc Plated / Hot-Dip Galvanized / Black Oxide / Dacromet |
| Product Grade | Grade A (M1.6-M16); Grade B (M18-M64) per ISO 4032 |
| Certification | EN 10204 3.1 Material Certificate; ISO 9001 Quality System; Third-party inspection available upon request |
| Annual Capacity | 50,000 tons |
Ordering Information
When ordering DIN934 hex nuts, specify the following to ensure correct supply:
- Standard designation: DIN 934 or ISO 4032 (confirm which your drawing references)
- Nominal diameter and thread pitch: e.g., M20 (coarse) or M20x1.5 (fine)
- Property class: e.g., Class 8 for carbon steel, A4-80 for marine SS316
- Surface finish: e.g., HDG for hot-dip galvanized
- Quantity and delivery condition
Example ordering callout: ISO 4032 - M16 - 8 - HDG = Standard hex nut, 16 mm coarse thread, property class 8, hot-dip galvanized.
Contact
SINOFASTENER - Marine fastener supplier, M1.6-M64 DIN934 hex nuts in full carbon steel and stainless steel grades with EN 10204 3.1 material traceability. Annual capacity 50,000 tons. We supply complete material certificates and can cooperate with third-party inspection per classification society requirements.
Email:sales@sinofastener.com
Website: www.zlfastener.com | www.sinofastener.com
