SS 904L Socket Head Cap ScrewASTM A479 · ASME B18.3 · Manufacturer, stockist & exporter, India
Alloy 904L · UNS N08904
An SS 904L socket head cap screw is a screw with a cylindrical head and hexagon socket, made from SS 904L to ASTM A479. Allen-type cap screws are used where the head must sit flush or space is tight.
- ASTM A479
- 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
- Material
- ASTM A479
- Dimensions
- ASME B18.3 · DIN 912 / ISO 4762
- 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 |
|---|---|
| Material standard | ASTM A479 |
| Dimensional standard | ASME B18.3 · DIN 912 / ISO 4762 |
| 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 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
| 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 Socket Head Cap Screw 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 Socket Head Cap Screws for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiSS 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?
A nut in the same alloy, machined from ASTM A479 bar, unless the project specifies otherwise.
Which standard covers SS 904L socket head cap screws?
The material is ASTM A479; dimensions follow ASME B18.3 · DIN 912 / ISO 4762. Always state both on your purchase order, with the edition if your project specifies one.
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 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