SS 304L Heavy Hex NutASTM A194 · ASME B18.2.2 · Manufacturer, trader & exporter, India
AISI 304L · UNS S30403
An SS 304L heavy hex nut is a thicker and wider hexagon nut for pressure bolting. ASTM A194 8 where specified; confirm grade and class in the purchase specification. 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 A194
- 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 304L Heavy Hex Nut?
- What it is
- A thicker and wider hexagon nut for pressure bolting
- Finished spec
- ASTM A194 8 where specified
- Material / feedstock
- Within the finished specification (A194 8)
- Dimensions
- ASME B18.2.2
- Grade
- SS 304L · UNS S30403
- Best at
- Welded tanks, piping and vessels in general corrosive service
SS 304L Heavy Hex Nut Specification
| Product | SS 304L Heavy Hex Nut |
|---|---|
| Finished fastener specification | ASTM A194 8 where specified |
| Material / feedstock specification | Within the finished specification (A194 8) |
| Dimensional standard | ASME B18.2.2 |
| Manufacturing route | To the finished specification and purchase specification |
| Project / purchase specification | Yes — finished fastener requirements are to the purchase specification or project drawing |
| Sizes | M10 – M64 · ½" – 4" (others on request) |
| Threads | UNC · UN-8 · metric coarse |
| Testing | PMI (as specified in the PO) · dimensional · NDT and IGC on request |
| Documents | EN 10204 3.1 or 3.2 on request / as specified in the PO |
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 304L Heavy Hex Nut: Why 304L 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 304L, 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 304L is picked for welded tanks, piping and vessels in general corrosive service. |
|---|---|
| Typical service | Process piping — Welded lines in chemical and pharma plants. |
| Bolting | ASTM A193 B8 studs with A194 8 nuts |
SS 304L Heavy Hex Nut Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Chromium | As specified |
| Nickel | As specified |
| Carbon | As specified |
| Manganese | As specified |
| Silicon | As specified |
| Nitrogen | As specified |
| Phosphorus | As specified |
| Sulphur | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification to be verified: ASTM A240 for UNS S30403.
SS 304L Heavy Hex Nut Mechanical Properties
Under technical review for TDS.
| Property | Current requirement |
|---|---|
| Tensile strength | As specified |
| Yield strength 0.2% | As specified |
| Elongation | As specified |
| Hardness | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification and condition to be verified: ASTM A240 for UNS S30403 — Annealed plate & sheet.
Full chemistry, properties and equivalents are on the SS 304L grade page.
Other SS 304L fasteners
SS 304L 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 304L heavy hex nuts?
ASTM A194 8 heavy hex nuts.
Which standard covers SS 304L heavy hex nuts?
Finished fastener specification: ASTM A194 8 where specified. Material / feedstock: Within the finished specification (A194 8). Dimensions: ASME B18.2.2. State the finished specification, material and dimensions on your purchase order or project drawing.
What decides the price of a SS 304L 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 or 3.2 certificates available on request / as specified in the PO; dimensional reports as required. PMI can be arranged depending on product and requirements, as specified in the PO.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026