SS304L Tube Sheet
The low-carbon counterpart to 304 — chosen specifically for welded joints in mild service, where 304's higher carbon content would otherwise risk sensitization at the weld heat-affected zone.
Chemical Composition
| Element | Min % | Max % |
|---|---|---|
| Chromium (Cr) | 18.0 | 20.0 |
| Nickel (Ni) | 8.0 | 12.0 |
| Carbon (C) | — | 0.030 |
| Manganese (Mn) | — | 2.0 |
Mechanical Properties
| Property | Typical Value |
|---|---|
| Tensile Strength | 485 MPa min |
| Yield Strength (0.2% offset) | 170 MPa min |
| Elongation | 40% min |
| Brinell Hardness | 201 HB max |
Equivalent Grades
| Standard | Designation |
|---|---|
| ASTM / UNS | S30403 |
| EN / DIN | 1.4307 |
| JIS | SUS304L |
SA-965 / F304L Specification
When a drawing or RFQ cites SA-965 / F304L (or ASTM A965 Grade F304L) with UNS S30403, 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.
| Element | Reference |
|---|---|
| Specification | ASTM A965 / A965M |
| ASME designation | SA-965 / SA-965M where applicable (edition-dependent; confirm Code context) |
| Grade designation | F304L |
| UNS | S30403 |
| 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. F304L is the listed grade designation that corresponds to UNS S30403 (SS304L). 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 SS304L / F304L / S30403 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 (F304L 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 (F304L) | Investigate when the material is specified as a forging for pressure/high-temperature parts |
For RFQ clarity, include where known: grade (SS304L), UNS (S30403), ASTM/ASME + edition, F-grade (F304L), product form (plate / forging / clad), drawing + revision, OD/thickness, hole pattern, quantity, and inspection/testing.
Continue from grade identity into product form and machining:
304L vs. 304 — Which One
See the full SS304 datasheet for the non-welded counterpart.
Available Product Forms
SS304L is available across all structural types, most often as Fixed Tube Sheets with welded joints in general chemical and light industrial service.
Applications
Any mild-service application where the tube-to-sheet joint is welded — food processing, general chemical service, and light industrial cooling where 316L's molybdenum isn't required by the fluid chemistry.
Advantages & Limitations
Advantages
- Lower cost than 316L for equivalent weldability
- No sensitization risk at weld joints
- Widely available, standard lead times
Limitations
- No molybdenum — same chloride limits as standard 304
- Slightly lower strength than 304 due to lower carbon
- Not suitable for chloride-bearing or seawater service
FAQ
Yes, as a general rule — the cost difference between 304 and 304L is typically small, and 304L removes the sensitization risk entirely for welded joints. There's rarely a good reason to weld standard 304 when 304L is available.
Yes, 304L is a fully code-recognized pressure vessel material under ASME Section VIII — its slightly lower allowable stress compared to 304 is accounted for in the standard thickness calculation, not a barrier to use.
304L is stocked in most common diameters alongside 304, given its similarly high demand for welded applications — confirm your specific size for immediate availability.