ASTM Standards for 1.4306 Stainless Steel
If you are sourcing 1.4306 stainless steel-whether in the form of plates, pipes, or bars-a key point to understand is that 1.4306 is a European material grade, whereas ASTM standards utilize American designations such as 304L and UNS S30403.
However, simply specifying "1.4306 stainless steel" is insufficient for international procurement. A proper specification should clearly detail the product form, ASTM standard, grade, dimensions, surface finish, heat treatment condition, testing requirements, and certification requirements.
What are the equivalent materials for 1.4306 stainless steel?
1.4306 generally corresponds to X2CrNi19-11, AISI 304L, and UNS S30403; it is a low-carbon austenitic stainless steel. Under EN material grade standards, it typically features a maximum carbon content of 0.03%, a chromium content of approximately 18%–20%, and a nickel content of approximately 10%–12%.
| Material | Common | Standard system | Typical carbon limit |
|---|---|---|---|
| 1.4306 | X2CrNi19-11 | EN | ≤0.03% |
| 304L | AISI 304L | AISI/ASTM | ≤0.03% |
| UNS S30403 | 304L | UNS/ASTM | ≤0.03% |
| 1.4307 | X2CrNi18-9 | EN | ≤0.03% |
ASTM Standards for 1.4306 / AISI 304L Stainless Steel
Here is a breakdown of the most commonly used ASTM standards relevant to 1.4306 / 304L stainless steel:
| Product | Common ASTM specification | Typical grade designation |
| Plate | ASTM A240/A240M | TP304L / UNS S30403 |
| Sheet | ASTM A240/A240M | 304L / UNS S30403 |
| Strip | ASTM A240/A240M | 304L / UNS S30403 |
| Seamless pipe | ASTM A312/A312M | TP304L / UNS S30403 |
| Welded pipe | ASTM A312/A312M | TP304L / UNS S30403 |
| Seamless tubing | ASTM A269/A269M | TP304L / UNS S30403 |
| Heat exchanger tube | ASTM A213/A213M | TP304L |
| Bar | ASTM A276/A276M | 304L / UNS S30403 |
| Forged components | Depending on application | 304L / S30403 |
| Flanges / fittings | Product-specific ASTM/ASME standard | 304L / S30403 |
ASTM A240 covers chromium and chromium-nickel stainless steel plate, sheet and strip for pressure-vessel and general applications.
ASTM A312 covers seamless, straight-seam welded and heavily cold-worked welded austenitic stainless steel pipe for high-temperature and general corrosive service.
ASTM A276 covers hot-finished and cold-finished stainless steel bars and shapes, including rounds, squares and hexagons.
ASTM A240 304L Sheet Specification
ASTM A240 covers 304L (1.4306) stainless steel in sheet, plate, and strip form. Key specification highlights:
Thickness Range: Typically from 0.3 mm to 50 mm
Finish Options: 2B, BA, No.4, No.8 (mirror)
Mechanical Properties (Annealed Condition):
Yield Strength (min): 170 MPa
Tensile Strength (min): 485 MPa
Elongation: ≥ 40%
Corrosion Resistance: Excellent in mildly corrosive environments
Applications: Pressure vessels, tanks, kitchen equipment, architectural panels
ASTM A276 304L Stainless Steel Bar Specification
ASTM A276 specifies hot-finished or cold-finished bars and shapes of stainless steel, including 1.4306 / AISI 304L:
Common Forms: Round bar, square bar, flat bar, hexagon bar
Surface Finish: Peeled, polished, ground, or turned
Applications: Shafts, fasteners, supports, and machined parts
Hardness: Typically below 95 HRB (annealed condition)
Formability & Weldability: Excellent, thanks to low carbon content
1.4306 vs 1.4307 vs 304L
Customers frequently confuse these three grades.
| Grade | Common designation | Carbon | Key point |
| 1.4306 | X2CrNi19-11 | ≤0.03% | Higher Cr/Ni EN 304L-family grade |
| 1.4307 | X2CrNi18-9 | ≤0.03% | Common EN low-carbon 304L-family grade |
| 304L | UNS S30403 | Low carbon | ASTM/AISI commercial designation |
| 304 | UNS S30400 | ≤0.08% | Standard-carbon 304 |
What ASTM Standard Should You Put on a Purchase Order?
A good purchase description should contain more information than:
"304L stainless steel."
A stronger specification would identify:
Product + ASTM standard + grade + dimensions + finish/condition + testing + certification
For example:
SS 304L Plate
ASTM A240/A240M 304L stainless steel plate, UNS S30403, solution annealed, 10 mm × 1500 mm × 6000 mm, 2B/No.1 finish as applicable, EN 10204 3.1 MTC.
SS 304L Pipe
ASTM A312/A312M TP304L seamless stainless steel pipe, UNS S30403, NPS 4, Schedule 40S, solution heat treated, hydrostatic or nondestructive testing as specified.
SS 304L Bar
ASTM A276/A276M 304L stainless steel round bar, UNS S30403, Ø50 mm, annealed, bright drawn surface, EN 10204 3.1 certification.
This format reduces ambiguity between the material grade and the product standard.
What Tests Should Be Requested for 1.4306 / 304L?
| Inspection item | Purpose |
| Chemical analysis | Confirms Cr, Ni, C and other alloying elements |
| Tensile test | Verifies tensile strength and yield strength |
| Elongation | Confirms ductility |
| Hardness test | Checks hardness against specification |
| Dimensional inspection | Confirms OD, thickness, length and tolerances |
| Surface inspection | Detects scratches, pits, scale and defects |
| PMI | Confirms alloy grade in critical applications |
| Hydrostatic test | Commonly required for applicable pipe orders |
| Eddy-current / NDT | Applicable to specified tubing/pipe requirements |
| Intergranular corrosion test | When required by purchase specification |
| MTC | Provides traceability and test results |
FAQ
Is 1.4306 the same as 304L?
1.4306 is generally considered the European equivalent to the 304L grade, though it is not strictly an ASTM grade. Before substituting materials, one should verify the European material number against the ASTM/UNS grade in accordance with the applicable product standards.
Does 304L have better weldability than 304?
304L is often the preferred choice for welded structural components because its lower carbon content reduces the risk of chromium carbide precipitation during welding.
Does 304L offer good corrosion resistance?
Yes. While 304L offers good general corrosion resistance, it is not suitable for all environments. In conditions involving high chloride concentrations, high temperatures, crevice environments, or specific chemical media, materials such as 316L or higher alloy grades may be required.
What kind of certification should be requested for 304L stainless steel?
For industrial procurement requiring certification and traceability, an EN 10204 3.1 material test certificate is typically required. This certificate should specify the heat/batch number, material grade, chemical composition, and relevant mechanical properties or test results.
