SS 310 / 310S Expander FlangeASTM A182 · ASME B16.5 (flange end) · Manufacturer, stockist & exporter, India
AISI 310S · UNS S31008 · EXP
An SS 310 / 310S expander flange is a weld neck flange whose hub increases the pipe size, made from SS 310 / 310S to ASTM A182 F310. Expander flanges step up the line size at a pump or valve outlet, replacing a reducer and a standard weld neck flange with one part.
- ASTM A182
- ASME B16.5 (flange end)
- EN 10204 3.1 / 3.2
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is an SS 310 / 310S Expander Flange?
- What it is
- A weld neck flange whose hub increases the pipe size
- Material
- ASTM A182 F310
- Dimensions
- ASME B16.5 (flange end)
- Grade
- SS 310 / 310S · UNS S31008
- Best at
- Furnaces, burners and heat treatment at high temperature
SS 310 / 310S Expander Flange Specification
| Product | SS 310 / 310S Expander Flange |
|---|---|
| Material standard | ASTM A182 F310 |
| Dimensional standard | ASME B16.5 (flange end) |
| Sizes | ½" – 24" (ASME B16.5) · 26" – 60" (ASME B16.47) |
| Pressure class | Class 150, 300, 400, 600, 900, 1500, 2500 · PN 6 – PN 100 |
| Facing | RF · FF · RTJ · tongue & groove |
| Bore | To match pipe schedule (state on order) |
| Testing | PMI · dimensional · NDT and IGC on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
When to Choose an Expander Flange
Expander flanges step up the line size at a pump or valve outlet, replacing a reducer and a standard weld neck flange with one part.
- Increases one or two pipe sizes
- Saves a weld and space
- Weld neck design
More on choosing: Expander flange guide.
SS 310 / 310S Expander Flange: Why 310S for expander flanges
Expander flanges step up the line size at a pump or valve outlet, replacing a reducer and a standard weld neck flange with one part. In SS 310 / 310S, 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 flanges are chosen where carbon steel would rust or contaminate the process. SS 310 / 310S is picked for furnaces, burners and heat treatment at high temperature. |
|---|---|
| Typical service | Furnace parts — Muffles, retorts, radiant tubes and conveyor belts. |
| Bolting | A193 B8 or project-specified bolting |
| Welding to carbon steel | ER309L (or E309L electrode) is the usual filler when joining it to carbon steel |
| Matching filler | ER310 (AWS A5.9) |
SS 310 / 310S Expander Flange Chemical Composition
| Element | Weight % |
|---|---|
| Chromium | 24.0 – 26.0 |
| Nickel | 19.0 – 22.0 |
| Carbon | 0.08 max |
| Manganese | 2.00 max |
| Silicon | 1.50 max |
| Phosphorus | 0.045 max |
| Sulphur | 0.030 max |
| Iron | Balance |
SS 310 / 310S Expander Flange Mechanical Properties
| Annealed plate & sheet | Value |
|---|---|
| Tensile strength | 515 MPa · 75 ksi |
| Yield strength 0.2% | 205 MPa · 30 ksi |
| Elongation | 40% |
| Hardness | 217 HB max |
Full chemistry, properties and equivalents are on the SS 310 / 310S grade page.
Other SS 310 / 310S flanges
SS 310 / 310S Expander Flanges for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiSS 310 / 310S Expander Flange — questions buyers ask
When is an expander flange used?
Most often at pump and valve outlets where the line size increases immediately.
Can SS 310 / 310S expander flanges be welded to carbon steel?
Yes — ER309L (or E309L electrode) is the usual filler when joining it to carbon steel.
Which standard covers SS 310 / 310S expander flanges?
The material is ASTM A182 F310; dimensions follow ASME B16.5 (flange end). Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a SS 310 / 310S expander flange?
The alloy price, the size and pressure class, 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