Stainless Steel 304 / 304L Seamless Pipes & Tubes Manufacturer & Supplier
SS 304 / 304L (UNS S30400 / S30403) are the most widely used austenitic stainless steel grades. 304 is the standard 18/8 grade offering excellent corrosion resistance and formability. 304L is the low-carbon variant (C: 0.030% max) that prevents carbide precipitation during welding, making it preferred for welded fabrication and cryogenic applications.
UNS: S30400 / S30403 | Category: Austenitic Stainless Steel | Werkstoff Nr: 1.4301 / 1.4307 | EN Name: X5CrNi18-10 / X2CrNi18-9
SS 304 / 304L — Also Known As
SS 304 / 304L is also commonly known as SS 304 / 304L, Stainless Steel 304 / 304L Seamless Pipes & Tubes, S30400 / S30403, UNS S30400 / S30403, 1.4301 / 1.4307, Werkstoff 1.4301 / 1.4307, W.Nr 1.4301 / 1.4307, X5CrNi18-10 / X2CrNi18-9, 304, 304l, 304/304l, 304l/304, s30400, s30403.
SS 304 / 304L — Applicable Standards & Specifications
SS 304 / 304L is commonly supplied to ASTM A312, ASME SA312, ASTM A213, ASME SA213, ASME SA269, ASTM A376, ASME SA376, EN 10216-5.
Size Range
Outer Diameter: 1/4" NPS to 10" NPS (6.35mm to 273.1mm OD)
Wall Thickness: SCH 5S to SCH 160, XXS
Chemical Composition (%)
| C | Mn | Si | Cr | Ni | P | S |
|---|---|---|---|---|---|---|
| 0.08 / 0.030 max | 2.00 max | 0.75 max | 18.0-20.0 | 8.0-10.5 / 8.0-12.0 | 0.045 max | 0.030 max |
Mechanical Properties
- Tensile Strength
- 515 / 485 MPa min
- Yield Strength
- 205 / 170 MPa min
- Elongation
- 35% min
- Hardness
- 92 HRB max
Physical Properties
- Density
- 7.93 g/cm3
- Melting Range
- 1400-1450 C
- Thermal Conductivity
- 16.2 W/m-K
- Electrical Resistivity
- 720 nOhm-m
- Specific Heat
- 500 J/kg-K
- Coeff. of Thermal Expansion
- 17.2 um/m-C
Corrosion Resistance
- Pitting Resistance (PREN)
- ~18
- Max Service Temp (Oxidizing)
- 870 C
- Intergranular Corrosion
- 304: Susceptible if sensitized / 304L: Resistant (low carbon)
- Stress Corrosion Cracking
- Susceptible in chlorides >60C
- General Corrosion Rate
- <0.1 mm/yr in mild acids
- Seawater Resistance
- Limited - pitting risk
Applicable Standards
- ASTM A312 / ASME SA312
- ASTM A213 / ASME SA213
- ASTM A269
- DIN EN 10216-5
Applications
- General corrosion-resistant piping
- Food & beverage processing
- Chemical processing equipment
- Welded structures (304L preferred)
- Heat exchangers
- Pharmaceutical equipment
- Cryogenic vessels and piping (304L)
- Nuclear industry applications (304L)
- Semiconductor fab bulk gas (N2, CDA) and process cooling water headers (304L)
Industries Served
- Food & Beverage
- Chemical Processing
- Architecture
- Pharmaceutical
- Water Treatment
- Petrochemical
- Nuclear Energy
- Semiconductor & Electronics
Key Advantages
- Excellent general corrosion resistance
- Superior formability and weldability
- 304L: Resistant to intergranular corrosion after welding
- 304L: Excellent cryogenic toughness down to -196C
- Non-magnetic in annealed condition
- Wide availability and most cost-effective austenitic grade
Equivalent Grades
- ASTM
- TP304 / TP304L
- JIS
- SUS 304 / SUS 304L
- BS
- 304S31 / 304S11
- GOST
- 08Kh18N10 / 03Kh18N11
Frequently Asked Questions
Ss 304l seamless pipes supplier india — what should buyers know?
In India, SS 304L seamless pipes are supplied to ASTM A312 / ASME SA312 in TP304L grade, with low carbon content for improved weldability and corrosion resistance. Standard sizes typically cover 1/8 inch to 24 inch NPS, in SCH 5S to SCH XXS, with annealed, pickled, and tested tubes available to ASTM A213 and A269 where required.
What is the difference between SS 304 and 304L seamless pipes?
SS 304L seamless pipes have a lower carbon limit than 304, which reduces carbide precipitation during welding and helps maintain corrosion resistance in the heat-affected zone. Both are austenitic stainless steels, but 304L is generally preferred for welded fabrication, process piping, and corrosive service where post-weld heat treatment is not practical.
What specifications and tolerances apply to 304L seamless pipes in India?
SS 304L seamless pipes in India are commonly supplied to ASTM A312 / ASME SA312, while seamless tubes may follow ASTM A213 or ASTM A269 depending on service. Dimensional tolerances are governed by the relevant ASTM standard and pipe schedule, with wall thickness, outside diameter, length, straightness, and test requirements such as hydrostatic or nondestructive electric testing specified accordingly.
What specifications should an SS 304L seamless pipe supplier in India provide?
A reliable supplier should state the product standard, grade, size, wall thickness, finish, test certificates, and inspection scope. For 304L seamless pipes, the common references are ASTM A312 TP304L for process piping, ASTM A213 TP304L for heat-exchanger service, and ASTM A269 for instrumentation or general service tubes.
What is the difference between SS 304 and SS 304L seamless pipes?
The main difference is carbon content. SS 304L is the low-carbon version of 304, limited to 0.03% max carbon, which reduces carbide precipitation during welding and lowers the risk of intergranular corrosion. Mechanical properties are similar for most piping uses, so 304L is often chosen when fabrication or welding is involved.
What specifications should an SS 304L seamless pipes supplier in India provide?
A reliable Indian supplier should state the material grade as TP304L / UNS S30403 and quote the governing standard, usually ASTM A312 or ASME SA312 for seamless pipe. Buyers should also check size range, schedule, finish, test requirements, dimensional tolerances to ASME B36.19M or ASTM A999, and availability of mill test certificates.
Which standards and tolerances apply to 304L seamless pipes supplied in India?
SS 304L seamless pipes are typically supplied to ASTM A312 for pipe applications and ASTM A213 or A269 for tube applications, depending on end use. Dimensions, wall thickness, and schedules follow ASME/ASTM standard tables, while tolerances are controlled by the relevant product specification and verified through mill test certification and inspection records.