SS 904L Socket Head Cap ScrewUNS N08904 · ASME B18.3 · Manufacturer, trader & exporter, India
Alloy 904L · UNS N08904
An SS 904L socket head cap screw is a screw with a cylindrical head and hexagon socket. Finished fastener specification not asserted; may be machined from ASTM A479 bar (UNS N08904), where applicable; finished fastener requirements are to the purchase specification or project drawing. Allen-type cap screws are used where the head must sit flush or space is tight.
See the SS 904L fasteners grade form page for standards and sizes.
- UNS N08904
- ASME B18.3
- 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 Socket Head Cap Screw?
- What it is
- A screw with a cylindrical head and hexagon socket
- Finished spec
- Not asserted
- Material / feedstock
- ASTM A479 bar (UNS N08904), where applicable
- Dimensions
- ASME B18.3 · ISO 4762 · DIN 912 (legacy DIN)
- Grade
- SS 904L · UNS N08904
- Best at
- Dilute sulphuric acid, phosphoric acid and chloride-bearing cooling water
SS 904L Socket Head Cap Screw Specification
| Product | SS 904L Socket Head Cap Screw |
|---|---|
| Finished fastener specification | Not asserted |
| Material / feedstock specification | ASTM A479 bar (UNS N08904), where applicable |
| Dimensional standard | ASME B18.3 · ISO 4762 · DIN 912 (legacy DIN) |
| Manufacturing route | May be machined from bar, where applicable |
| 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 Socket Head Cap Screw
Allen-type cap screws are used where the head must sit flush or space is tight.
- Hex socket drive
- ASME B18.3 · DIN 912
- Metric and inch
More on choosing: Socket head cap screw guide.
SS 904L Socket Head Cap Screw: Why 904L for socket head cap screws
Allen-type cap screws are used where the head must sit flush or space is tight. 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 Socket Head Cap Screw Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Nickel | As specified |
| Chromium | As specified |
| Molybdenum | As specified |
| Copper | As specified |
| Carbon | As specified |
| Manganese | As specified |
| Silicon | As specified |
| Nitrogen | 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 N08904.
SS 904L Socket Head Cap Screw 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 N08904 — Annealed plate & sheet.
Full chemistry, properties and equivalents are on the SS 904L grade page.
Standards on this page
Other SS 904L fasteners
SS 904L Socket Head Cap Screw — questions buyers ask
DIN 912 and ISO 4762 — are they the same?
Yes, ISO 4762 replaced DIN 912 with the same main dimensions.
What nut is used with SS 904L socket head cap screws?
Usually a nut in the same alloy — it may be machined from ASTM A479 bar, where applicable; finished requirements are to the purchase specification or project drawing.
Which standard covers SS 904L socket head cap screws?
Finished fastener specification: Not asserted. Material / feedstock: ASTM A479 bar (UNS N08904), where applicable. Dimensions: ASME B18.3 · ISO 4762 · DIN 912 (legacy DIN). State the finished specification, material and dimensions on your purchase order or project drawing.
What decides the price of a SS 904L socket head cap screw?
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