SS310 Tube Sheet
The highest chromium and nickel content in the standard stainless family gives 310 the best oxidation resistance of any austenitic grade — the reach before moving to Inconel or Incoloy for extreme continuous high-temperature exposure.
Chemical Composition
| Element | Min % | Max % |
|---|---|---|
| Chromium (Cr) | 24.0 | 26.0 |
| Nickel (Ni) | 19.0 | 22.0 |
| Silicon (Si) | — | 1.50 |
| Carbon (C) | — | 0.25 |
Mechanical Properties
| Property | Typical Value |
|---|---|
| Tensile Strength | 515 MPa min |
| Yield Strength (0.2% offset) | 205 MPa min |
| Elongation | 40% min |
| Continuous Oxidation Resistance | ~1035-1150°C |
Equivalent Grades
| Standard | Designation |
|---|---|
| ASTM / UNS | S31000 |
| EN / DIN | 1.4841 |
| JIS | Confirm purchaser JIS product standard — do not auto-map S31000 to SUS310S |
UNS S31000 (SS310) is not the same as UNS S31008 (SS310S). SUS310S is the common JIS label for the low-carbon 310S counterpart — treat it as a related designation only when the purchaser documents that mapping.
SA-965 / F310 Specification
When a drawing or RFQ cites SA-965 / F310 (or ASTM A965 Grade F310) with UNS S31000, it is pointing at an austenitic stainless-steel forging path — not a universal “tube sheet standard.” Confirm the ordered product form, grade designation and purchaser requirements against the drawing before procurement.
SS310 ≠ SS310S. F310 corresponds to UNS S31000 (SS310). Do not equate this path with SS310S (UNS S31008) or invent an A965 F310S designation — A965 lists F310, not F310S.
| Element | Reference |
|---|---|
| Specification | ASTM A965 / A965M |
| ASME designation | SA-965 / SA-965M where applicable (edition-dependent; confirm Code context) |
| Grade designation | F310 |
| UNS | S31000 |
| Product form | Austenitic stainless-steel forging |
| Application context | Pressure and high-temperature parts, subject to project requirements |
A965/SA-965 covers austenitic stainless-steel forgings for boilers, pressure vessels, high-temperature parts and associated equipment. F310 is the listed grade designation that corresponds to UNS S31000 (SS310). The finished tube-sheet geometry, machining, hole pattern and inspection scope remain purchaser / drawing requirements — they are not defined by naming A965 or SA-965 alone.
Do not treat A240, A182 and A965 as interchangeable. A practical procurement path when SS310 / F310 / S31000 appears on a drawing:
| Specification | Product form / role | How to read it for tube sheets |
|---|---|---|
| ASTM A240 / SA-240 | Plate, sheet and strip | Common plate path when the blank is machined from flat product |
| ASTM A182 / SA-182 | Forged / rolled piping components (F310 context) | Relevant when the callout is piping-component forging scope; confirm against the ordered part — do not assume A182 purchases a large forged tube-sheet blank |
| ASTM A965 / SA-965 | Austenitic stainless-steel forgings (F310) | Investigate when the material is specified as a forging for pressure/high-temperature parts |
For RFQ clarity, include where known: grade (SS310), UNS (S31000), ASTM/ASME + edition, F-grade (F310), product form (plate / forging / clad), drawing + revision, OD/thickness, hole pattern, quantity, and inspection/testing.
Continue from grade identity into product form and machining:
A Necessary Caveat on Temperature Numbers
Available Product Forms
SS310 is most often specified as a U-Tube Tube Sheet for furnace, kiln-adjacent, and high-temperature process gas equipment.
Applications
Furnace components, heat-treating equipment, and high-temperature process gas heat exchangers where extreme oxidation resistance is the primary driver rather than pressure-boundary strength at temperature.
Advantages & Limitations
Advantages
- Best oxidation resistance in the standard stainless family
- Good resistance to carburizing and sulfur-bearing atmospheres
- Lower cost than nickel alloys for equivalent oxidation duty
Limitations
- Allowable stress at high temperature is limited despite oxidation resistance
- No chloride advantage — still no molybdenum
- 310S (lower carbon) generally preferred for welded applications
FAQ
310S, with its lower carbon content, is generally preferred for welded applications for the same sensitization-avoidance reason 304L is preferred over 304. See the SS310S datasheet for the low-carbon variant.
Only within limits — 310 handles oxidation well but has lower allowable stress at extreme temperature and less resistance to certain aggressive atmospheres than Inconel. It's a cost-effective step below Inconel, not a full substitute for the most demanding services.
310 is typically sourced to order given its specialist high-temperature demand profile — send your specification and quantity for a confirmed lead time.