SS 904L Heavy Hex NutASTM B649 · ASME B18.2.2 · Manufacturer, stockist & exporter, India
Alloy 904L · UNS N08904
An SS 904L heavy hex nut is a thicker and wider hexagon nut for pressure bolting, made from SS 904L to ASTM B649. 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 B649
- 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 SS 904L Heavy Hex Nut?
- What it is
- A thicker and wider hexagon nut for pressure bolting
- Material
- ASTM B649
- Dimensions
- ASME B18.2.2
- Grade
- SS 904L · UNS N08904
- Best at
- Dilute sulphuric acid, phosphoric acid and chloride-bearing cooling water
SS 904L Heavy Hex Nut Specification
| Product | SS 904L Heavy Hex Nut |
|---|---|
| Material standard | ASTM B649 |
| 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.
SS 904L Heavy Hex Nut: Why 904L 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 SS 904L, 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 | Stainless fasteners resist atmospheric and process corrosion. SS 904L is picked for dilute sulphuric acid, phosphoric acid and chloride-bearing cooling water. |
|---|---|
| Typical service | Sulphuric acid plants — Coolers, piping and tanks for dilute sulphuric acid. |
| Bolting | as the project specifies |
SS 904L Heavy Hex Nut Chemical Composition
| Element | Weight % |
|---|---|
| Nickel | 23.0 – 28.0 |
| Chromium | 19.0 – 23.0 |
| Molybdenum | 4.0 – 5.0 |
| Copper | 1.0 – 2.0 |
| Carbon | 0.020 max |
| Manganese | 2.00 max |
| Silicon | 1.00 max |
| Nitrogen | 0.10 max |
SS 904L Heavy Hex Nut Mechanical Properties
| Annealed plate & sheet | Value |
|---|---|
| Tensile strength | 490 MPa · 71 ksi |
| Yield strength 0.2% | 220 MPa · 31 ksi |
| Elongation | 35% |
| Hardness | 90 HRB max |
Full chemistry, properties and equivalents are on the SS 904L grade page.
Standards on this page
Other SS 904L fasteners
SS 904L Heavy Hex Nuts for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiSS 904L 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 SS 904L heavy hex nuts?
A nut in the same alloy, machined from ASTM B649 bar, unless the project specifies otherwise.
Which standard covers SS 904L heavy hex nuts?
The material is ASTM B649; 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 SS 904L 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.
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