Hex Jam Nuts
What are Hex Jam Nuts?
A Hex Jam Nut is a thin, six-sided internally threaded fastener used as a locking nut when paired with a standard hex nut. It is typically tightened against the primary nut to prevent loosening due to vibration or dynamic loads. Hex jam nuts are widely used in assemblies where space is limited, or where secondary locking strength is required without the use of chemical adhesives or washers.
Ideal for automotive, industrial, and machinery applications, hex jam nuts provide a low-profile solution for secure, vibration-resistant fastening.
Key Features
Leak-Proof
Jointing
Durable
Construction
Easy Installation
& Removal
Wide
Compatibility
Corrosion
Resistant
Specifications
| Specification Category | Parameter / Feature | Details / Options |
|---|---|---|
| Size Range | Nominal Size | M3 to M48 (custom sizes available) |
| Pressure Ratings | ANSI / ASME Class | Class 150, 300, 600, 900, 1500, 2500 |
| PN Ratings | PN6, PN10, PN16, PN25, PN40, PN64 | |
| Product Types | Hex Jam Nuts | Standard Hex Jam, Thin Hex, Stainless Steel, Carbon Steel, Alloy Steel |
| Material Options | Steel Grades | Carbon Steel (ASTM A194, A563), Stainless Steel (SS 304, 316, 316L), Alloy Steel |
| Other Alloys | Nickel Alloys, Inconel, Titanium (Grade 2, Grade 5) | |
| Standards & Certifications | ASTM | ASTM A194, ASTM A563 |
| ASME / ANSI | ASME B18.2.2 | |
| European Standards | DIN 439, ISO 4033 | |
| Certifications | ISO 9001, PED 2014/68/EU, NACE MR0175 | |
| Design Features | Thread Type | Coarse / Fine / Metric / UNC / UNF |
| Surface Finish | Plain, Zinc Plated, Nickel Plated, Hot-Dip Galvanized | |
| Tolerance | As per ASTM / ISO / DIN standards | |
| Coating & Surface Finish | Anti-Corrosion Coating | Zinc Plating, Nickel Plating, Hot-Dip Galvanized |
| Optional Coatings | PTFE, PVD, Anodizing | |
| Surface Finish | Plain, Polished, Passivated | |
| Testing & Inspection | Mechanical Testing | Tensile, Hardness, Impact |
| Non-Destructive Testing | Magnetic Particle (MPI), Dye Penetrant (DPT) | |
| Pressure Testing | Applicable for pressure-rated nuts, Hydrostatic / Pneumatic |
Dimensions
| Thread Size (Metric) | Width Across Flats (WAF) | Width Across Corners | Thickness | Pitch | Standard |
|---|---|---|---|---|---|
| M3 | 5.5 mm | 6.0 mm | 2.4 mm | 0.5 mm | DIN 439 / ISO 4033 |
| M4 | 7 mm | 7.8 mm | 2.8 mm | 0.7 mm | DIN 439 / ISO 4033 |
| M5 | 8 mm | 9.2 mm | 3.2 mm | 0.8 mm | DIN 439 / ISO 4033 |
| M6 | 10 mm | 11.0 mm | 3.5 mm | 1.0 mm | DIN 439 / ISO 4033 |
| M8 | 13 mm | 14.4 mm | 4.5 mm | 1.25 mm | DIN 439 / ISO 4033 |
| M10 | 17 mm | 18.5 mm | 6 mm | 1.5 mm | DIN 439 / ISO 4033 |
| M12 | 19 mm | 21.0 mm | 7 mm | 1.75 mm | DIN 439 / ISO 4033 |
| M14 | 22 mm | 24.0 mm | 8 mm | 2.0 mm | DIN 439 / ISO 4033 |
| M16 | 24 mm | 26.5 mm | 10 mm | 2.0 mm | DIN 439 / ISO 4033 |
| M18 | 27 mm | 30.0 mm | 11 mm | 2.5 mm | DIN 439 / ISO 4033 |
| M20 | 30 mm | 33.0 mm | 12 mm | 2.5 mm | DIN 439 / ISO 4033 |
| M22 | 33 mm | 36.0 mm | 14 mm | 2.5 mm | DIN 439 / ISO 4033 |
| M24 | 36 mm | 39.0 mm | 16 mm | 3.0 mm | DIN 439 / ISO 4033 |
| M27 | 41 mm | 45.0 mm | 18 mm | 3.0 mm | DIN 439 / ISO 4033 |
| M30 | 46 mm | 50.0 mm | 20 mm | 3.5 mm | DIN 439 / ISO 4033 |
| M36 | 55 mm | 60.0 mm | 24 mm | 4.0 mm | DIN 439 / ISO 4033 |
| M42 | 65 mm | 70.0 mm | 28 mm | 4.5 mm | DIN 439 / ISO 4033 |
| M48 | 75 mm | 80.0 mm | 32 mm | 5.0 mm | DIN 439 / ISO 4033 |
Mechanical Properties
| Property | Value | Unit / Standard |
|---|---|---|
| Tensile Strength | 400 – 900 | MPa (Carbon Steel, Stainless Steel, Alloy Steel) |
| Yield Strength | 200 – 500 | MPa |
| Hardness | 120 – 250 | HB (Brinell) |
| Elongation | ≥ 10 – 25 | % |
| Density | 7.8 – 8.0 | g/cm³ |
| Impact Toughness | ≥ 20 – 60 | J (Charpy, grade-dependent) |
| Modulus of Elasticity (E) | ~200 | GPa |
| Fatigue Strength | 200 – 400 | MPa |
| Corrosion Resistance | Good to Excellent (SS > CS > Alloy Steel) | – |
| Thermal Conductivity | 15 – 50 | W/m·K |
| Coefficient of Thermal Expansion | 10 – 17 ×10⁻⁶ | /°C |
| Yield Ratio (YS/UTS) | 0.40 – 0.65 | – |
| Poisson’s Ratio | 0.27 – 0.30 | – |
| Brinell Hardness Range | 120 – 250 | HB |
| Surface Finish | Plain / Serrated / Zinc-Plated / Nickel-Plated | – |
| Thread Type | Metric / UNC / UNF | ISO / ANSI Standards |
| Operating Temperature Range | -40 to 600 | °C (material-dependent) |
| Standard Reference | DIN 439 / ISO 4033 / ASME B18.2.2 | – |
Chemical Composition
| Element | SS 304 (%) | SS 304L (%) | SS 316 (%) | SS 316L (%) |
|---|---|---|---|---|
| Chromium (Cr) | 18.0 – 20.0 | 18.0 – 20.0 | 16.0 – 18.0 | 16.0 – 18.0 |
| Nickel (Ni) | 8.0 – 10.5 | 8.0 – 12.0 | 10.0 – 14.0 | 10.0 – 14.0 |
| Carbon (C) | ≤ 0.08 | ≤ 0.03 | ≤ 0.08 | ≤ 0.03 |
| Manganese (Mn) | ≤ 2.00 | ≤ 2.00 | ≤ 2.00 | ≤ 2.00 |
| Silicon (Si) | ≤ 1.00 | ≤ 1.00 | ≤ 1.00 | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.045 | ≤ 0.045 | ≤ 0.045 | ≤ 0.045 |
| Sulfur (S) | ≤ 0.030 | ≤ 0.030 | ≤ 0.030 | ≤ 0.030 |
| Iron (Fe) | Balance | Balance | Balance | Balance |
| Molybdenum (Mo) | — | — | 2.0 – 3.0 | 2.0 – 3.0 |
Applications of Hex Jam Nuts
Construction &
Infrastructure
Automotive & Heavy
Equipment
Manufacturing &
Fabrication
Medical & Laboratory
Equipment
Electrical &
Electronics Assembly
Oil, Gas & Petrochemical
Installations
Do you have questions?
How does a hex jam nut work?
Can hex jam nuts be used on their own?
Are hex jam nuts available in stainless steel?
Do you supply jam nuts in bulk for industrial use?
