Hex Nuts
A six-sided metric nut manufactured to DIN 934, ISO 4032 and IS 1364-3 for reliable high-strength bolted joints. Available in Grade 8 and Grade 10 high-tensile carbon steel, and across an extended range in SS 304, SS 316 and SS 316L stainless steel for corrosion-critical environments.
What is a Hex Nut?
A hex nut is a six-sided internally threaded fastener designed to mate with a bolt or stud to clamp two or more components together. The hexagonal profile allows a spanner or socket to apply high torque efficiently, making it the most widely used nut in structural, mechanical and industrial assembly. Manufactured to DIN 934 / ISO 4032 / IS 1364-3, hex nuts in Grade 8 and Grade 10 are specified for high-load, vibration-critical bolted joints where proof load and yield strength are paramount. Thread tolerance class 6H ensures consistent fit with standard metric bolts across the entire size range.
Standards & Specifications
Hex nuts are manufactured and tested to the following international and Indian standards, covering dimensional tolerances, mechanical properties and thread form:
- DIN 934 / ISO 4032 — Hexagon nuts, style 1. Defines across-flat dimensions, thickness and chamfer geometry for metric coarse and fine pitch.
- IS 1364-3 — Indian standard equivalent to ISO 4032, mandatory for projects under BIS scope.
- IS 4218 / ISO 261 / ISO 965 — ISO metric thread form; thread tolerance class 6H for all grades.
Technical Drawing & Dimensional Tolerances
Key dimensions: s = Width across flats · e = Width across corners (min) · m = Nut thickness
| Size | Pitch (P) | A/F — s (mm) | A/C — e min (mm) | Thickness — m (mm) |
|---|---|---|---|---|
| M3 | 0.50 | 5.50 | 6.01 | 2.40 |
| M4 | 0.70 | 7.00 | 7.66 | 3.20 |
| M5 | 0.80 | 8.00 | 8.79 | 4.00 |
| M6 | 1.00 | 10.00 | 11.05 | 5.00 |
| M8 | 1.25 | 13.00 | 14.38 | 6.50 |
| M10 | 1.50 | 16.00 | 17.77 | 8.00 |
| M12 | 1.75 | 18.00 | 20.03 | 10.00 |
| M14 | 2.00 | 21.00 | 23.36 | 11.00 |
| M16 | 2.00 | 24.00 | 26.75 | 13.00 |
All dimensions in mm per DIN 934 / ISO 4032 — Product Grade A. Thread tolerance class 6H. Tolerances on s: −0 / −0.36 mm (M3–M6) to −0 / −0.52 mm (M14–M16).
Sizes Available
High-tensile Grade 8 and Grade 10 are stocked in both standard (coarse) pitch and fine pitch within the M3–M16 range. Fine pitch nuts offer finer thread engagement for vibration-critical applications.
| Size × Pitch | Grade 8 | Grade 10 |
|---|---|---|
| M3 × 0.5 | ✓ | — |
| M4 × 0.7 | ✓ | — |
| M5 × 0.8 | ✓ | — |
| M6 × 1 | ✓ | ✓ |
| M8 × 1.25 | ✓ | ✓ |
| M10 × 1.5 | ✓ | ✓ |
| M12 × 1.75 | ✓ | ✓ |
| M14 × 2 | ✓ | ✓ |
| M16 × 2 | ✓ | ✓ |
| Size × Pitch | Grade 8 | Grade 10 |
|---|---|---|
| M8 × 1 | ✓ | ✓ |
| M10 × 1.25 | ✓ | ✓ |
| M12 × 1.25 | ✓ | ✓ |
| M12 × 1.5 | ✓ | ✓ |
| M14 × 1.5 | ✓ | ✓ |
| M16 × 1.5 | ✓ | ✓ |
Applications
Grade 8 and Grade 10 hex nuts are the preferred choice wherever bolted joints are subject to high clamping loads, dynamic forces or vibration. Their controlled proof load ensures the nut does not strip or yield before the bolt, maintaining joint integrity under service loads.