Inconel 718 Heavy Hex NutASTM B637 · ASME B18.2.2 · Manufacturer, stockist & exporter, India
Alloy 718 · UNS N07718
An Inconel 718 heavy hex nut is a thicker and wider hexagon nut for pressure bolting, made from Inconel 718 to ASTM B637. Heavy hex nuts go with stud bolts on flanges. They spread load better and resist thread stripping at high preload. Made to ASME B18.2.2.
- ASTM B637
- ASME B18.2.2
- EN 10204 3.1 / 3.2
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is an Inconel 718 Heavy Hex Nut?
- What it is
- A thicker and wider hexagon nut for pressure bolting
- Material
- ASTM B637
- Dimensions
- ASME B18.2.2
- Grade
- Inconel 718 · UNS N07718
- Best at
- Very high strength at temperatures up to about 650 °C
Inconel 718 Heavy Hex Nut Specification
| Product | Inconel 718 Heavy Hex Nut |
|---|---|
| Material standard | ASTM B637 |
| Dimensional standard | ASME B18.2.2 |
| Sizes | M10 – M64 · ½" – 4" (others on request) |
| Threads | UNC · UN-8 · metric coarse |
| Testing | PMI · dimensional · NDT and IGC on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
When to Choose a Heavy Hex Nut
Heavy hex nuts go with stud bolts on flanges. They spread load better and resist thread stripping at high preload. Made to ASME B18.2.2.
- Thicker than standard hex nuts
- ASME B18.2.2
- Paired with A193 studs
More on choosing: Heavy hex nut guide.
Inconel 718 Heavy Hex Nut: Why 718 for heavy hex nuts
Heavy hex nuts go with stud bolts on flanges. They spread load better and resist thread stripping at high preload. Made to ASME B18.2.2. In Inconel 718, the choice usually comes down to the medium and temperature — the rows here are the points buyers check for this exact combination.
| Why this grade | Nickel-alloy fasteners match nickel-alloy flanges in corrosive or hot service. Inconel 718 is picked for very high strength at temperatures up to about 650 °C. |
|---|---|
| Typical service | Oil & gas — Wellhead parts, hangers and high-strength bolting. |
| Bolting | B7 (coated), B8M or nickel-alloy studs such as Inconel 718 from ASTM B637, as the project specifies |
| Sour service | Listed in NACE MR0175 / ISO 15156-3 within its limits — state it on the order |
Inconel 718 Heavy Hex Nut Chemical Composition
| Element | Weight % |
|---|---|
| Nickel (+Co) | 50.0 – 55.0 |
| Chromium | 17.0 – 21.0 |
| Niobium + Tantalum | 4.75 – 5.50 |
| Molybdenum | 2.80 – 3.30 |
| Titanium | 0.65 – 1.15 |
| Aluminium | 0.20 – 0.80 |
| Carbon | 0.08 max |
| Iron | Balance |
Inconel 718 Heavy Hex Nut Mechanical Properties
| Solution-treated and aged | Value |
|---|---|
| Tensile strength | 1275 MPa · 185 ksi |
| Yield strength 0.2% | 1034 MPa · 150 ksi |
| Elongation | 12% |
Full chemistry, properties and equivalents are on the Inconel 718 grade page.
Standards on this page
Other Inconel 718 fasteners
Inconel 718 Heavy Hex Nuts for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiInconel 718 Heavy Hex Nut — questions buyers ask
Why use heavy hex nuts on flanges?
They provide more thread engagement and bearing area for the high preload flange joints need.
What nut is used with Inconel 718 heavy hex nuts?
A nut in the same alloy, machined from ASTM B637 bar, unless the project specifies otherwise.
Which standard covers Inconel 718 heavy hex nuts?
The material is ASTM B637; dimensions follow ASME B18.2.2. Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a Inconel 718 heavy hex nut?
The alloy price, the size and dimensions, quantity, and the testing and documents required. Send your list and we quote the same working day.
Can you supply Inconel 718 heavy hex nuts to NACE MR0175?
Yes. Inconel 718 is listed in NACE MR0175 / ISO 15156-3 within its limits; state NACE compliance on the order and it is confirmed on the certificate.
What documents do you supply?
EN 10204 3.1 mill certificates as standard, 3.2 with third-party inspection on request, plus dimensional and PMI reports.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026