Stainless Steel Heavy Hex Nut - Grade 202, 304, 316, A2, A2-70
Heavy hex nuts are larger and thicker versions of standard hex nuts. They offer enhanced strength and durability for heavy-duty applications like structural connections, pressure vessels, flanges, and machinery
Heavy Hex Nut – Technical Specification Table (Inch Series)
| Nominal Size (Inch) | Threads per Inch (UNC) | Width Across Flats (A/F) (in) | Width Across Corners (W) (in) | Thickness (H) (in) | Min. Proof Load (psi) |
| 1/4″ | 20 | 0.50 | 0.577 | 0.25 | 90,000 |
| 5/16″ | 18 | 0.56 | 0.650 | 0.31 | ~90,000 |
| 3/8″ | 16 | 0.63 | 0.721 | 0.34 | ~90,000 |
| 7/16″ | 14 | 0.75 | 0.866 | 0.38 | ~90,000 |
| 1/2″ | 13 | 0.88 | 1.010 | 0.44 | ~120,000 |
| 5/8″ | 11 | 1.06 | 1.225 | 0.56 | ~120,000 |
| 3/4″ | 10 | 1.25 | 1.443 | 0.62 | ~150,000 |
| 7/8″ | 9 | 1.44 | 1.650 | 0.75 | ~150,000 |
| 1″ | 8 | 1.63 | 1.886 | 0.88 | ~150,000 |
| 1-1/4″ | 7 | 2.00 | 2.309 | 1.06 | ~150,000 |
| 1-1/2″ | 6 | 2.38 | 2.750 | 1.25 | ~150,000 |
- These values can vary slightly based on specific standard (ASTM A563 Grade DH, ASTM A194 Grade 2H, etc.).
- Always consult the standard for precise tolerance and class fit.
Materials and Grades
| Grade / Standard | Material Type | Hardness (HRC) | Common Use |
| ASTM A563 Grade A | Low carbon steel | B68–C32 | General purpose |
| ASTM A563 Grade DH | Medium carbon steel | C24–C38 | Structural bolting (A325) |
| ASTM A194 Grade 2H | Alloy steel | C24–C38 | High temp/pressure flanges |
| ASTM F594 (SS) | Stainless steel 304/316 | - | Corrosion resistance |
- Thread Type: UNC (Unified Coarse Thread)
- Class: 2B (standard internal thread class)
- Tolerance: As per ASME B1.1
- Thread Fit: Standard fit for structural bolts
| Coating Type | Description |
| Plain (black) | No coating, indoor use |
| Zinc plated | Corrosion resistance, moderate strength |
| Hot-dip galvanized | Thick coating, requires oversize tapping |
| Phosphate & oiled | Lubrication and mild corrosion protection |
| Stainless steel | Ideal for corrosion-prone environments |
Heavy hex nuts are specifically engineered to offer increased load-bearing capacity, guaranteeing dependable and steadfast fastening in challenging settings. Additionally, they come in a range of grades, each tailored with distinct mechanical characteristics to meet varying needs.
Tensile Strength
≥700 MPa
Yield Strength
≥1100 MPa
Elongation
≥12%
Hardness Max
250 HB
Larger and Thicker
Increased Strength
Enhanced Bearing Surface
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