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ASTM A312 vs ASTM A358 Pipe
ASTM A312 vs ASTM A358 Pipe: Understanding the Difference for Industrial Applications
When sourcing stainless steel pipes for critical industrial projects, buyers often compare ASTM A312 Pipe and ASTM A358 Pipe specifications. Although both standards cover austenitic stainless steel piping products, they differ in manufacturing methods, pipe sizes, testing requirements, applications, and project suitability.
This guide explains the key differences between ASTM A312 and ASTM A358 stainless steel pipes, helping engineers, procurement teams, fabricators, and project managers select the right specification for their applications.
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What is ASTM A312 Pipe?
ASTM A312 / ASME SA312 is the standard specification for seamless, welded, and heavily cold-worked austenitic stainless steel pipes intended for high-temperature and corrosive service.
Popular grades include:
- ASTM A312 TP304 Pipe
- ASTM A312 TP304L Pipe
- ASTM A312 TP316 Pipe
- ASTM A312 TP316L Pipe
- ASTM A312 TP321 Pipe
- ASTM A312 TP321H Pipe
- ASTM A312 TP347 Pipe
- ASTM A312 TP347H Pipe
- ASTM A312 TP310 Pipe
- ASTM A312 UNS S31254 Pipe
What is ASTM A358 Pipe?
ASTM A358 covers electric fusion welded (EFW) austenitic chromium-nickel stainless steel pipes intended for corrosive and high-temperature service.
Unlike ASTM A312, ASTM A358 is generally used for larger diameter piping systems where seamless manufacturing becomes impractical or expensive.
- ASTM A358 Grade 304 Pipe
- ASTM A358 Grade 304L Pipe
- ASTM A358 Grade 316 Pipe
- ASTM A358 Grade 316L Pipe
- ASTM A358 Grade 321 Pipe
ASTM A312 vs ASTM A358 Pipe Comparison
| Feature | ASTM A312 Pipe | ASTM A358 Pipe |
|---|---|---|
| Manufacturing | Seamless, Welded & Cold Worked | Electric Fusion Welded (EFW) |
| Pipe Sizes | Small to Large Sizes | Mainly Large Diameters |
| Pressure Service | Excellent | Good |
| Cost | Higher for Large Sizes | More Economical |
| Applications | Process Piping | Large Industrial Systems |
| Corrosion Resistance | Excellent | Excellent |
Chemical Composition Comparison
| Grade | Chromium (%) | Nickel (%) | Molybdenum (%) |
|---|---|---|---|
| TP304 | 18-20 | 8-11 | - |
| TP316 | 16-18 | 10-14 | 2-3 |
Mechanical Properties Comparison
| Property | ASTM A312 | ASTM A358 |
|---|---|---|
| Tensile Strength | 515 MPa | 515 MPa |
| Yield Strength | 205 MPa | 205 MPa |
ASTM A312 Pipe Specifications
- Stainless Steel Seamless Pipes
- Welded Stainless Steel Pipes
- High Temperature Service
- Corrosive Service Conditions
- Austenitic Stainless Steel Materials
Common grades include A312 TP304, TP304L, TP316, TP316L, TP321, TP321H, TP347H and S31254.
ASTM A358 Pipe Specifications
- Electric Fusion Welded Stainless Steel Pipes
- Large Diameter Process Piping
- High Temperature Applications
- Corrosive Fluid Transport Systems
- ASTM A358 Class 1 Pipe
ASTM A312 TP304 vs TP304L Pipe
ASTM A312 TP304 Pipe
- Excellent Corrosion Resistance
- Good Mechanical Strength
- General Industrial Applications
ASTM A312 TP304L Pipe
- Low Carbon Content
- Improved Weldability
- Reduced Carbide Precipitation
ASTM A312 TP316 vs TP316L Pipe
ASTM A312 TP316 Pipe
- Contains Molybdenum
- Superior Corrosion Resistance
- Suitable for Marine Service
ASTM A312 TP316L Pipe
- Low Carbon Version
- Enhanced Weldability
- Improved Intergranular Corrosion Resistance
Applications of ASTM A312 & ASTM A358 Pipes
ASTM A312 Pipe Applications
- Oil & Gas Industries
- Petrochemical Plants
- Pharmaceutical Industries
- Food Processing Units
- Heat Exchangers
- Pressure Piping Systems
ASTM A358 Pipe Applications
- Refineries
- Power Plants
- LNG Facilities
- Offshore Platforms
- Desalination Plants
- Chemical Processing Industries
How to Choose Between ASTM A312 and ASTM A358?
Choose ASTM A312 Pipe When:
- High Pressure Service is Required
- Seamless Pipe is Specified
- Small to Medium Diameters are Needed
- Critical Process Systems are Involved
Choose ASTM A358 Pipe When:
- Large Diameter Piping is Required
- EFW Construction is Acceptable
- Cost Optimization is Important
- High Temperature Process Service is Required
Why Choose Kamal Piping?
Kamal Piping is a trusted manufacturer, supplier, stockist, and exporter of ASTM A312 and ASTM A358 stainless steel pipes. We offer ASTM A312 TP304, TP304L, TP316, TP316L, TP321, TP347H and ASTM A358 Grade 304, 304L, 316, 316L and 321 pipes with complete test certificates and export documentation.
Get Technical AssistanceFrequently Asked Questions
ASTM A312 covers seamless, welded and cold-worked austenitic stainless steel pipes for high-temperature and corrosive service.
ASTM A358 covers electric fusion welded stainless steel pipes used mainly in large diameter applications.
ASTM A312 includes seamless and welded pipes, whereas ASTM A358 primarily covers EFW stainless steel pipes.
ASTM A312 includes both seamless and welded stainless steel pipes.
Common grades include TP304, TP304L, TP316, TP316L, TP321, TP347H and S31254.
ASTM A358 Class 1 refers to a commonly specified EFW stainless steel pipe category for industrial service.
They are used in oil & gas, petrochemical, pharmaceutical, food processing and pressure piping systems.
The selection depends on pipe size, pressure requirements, manufacturing preference and project budget.
Understanding the difference between ASTM A312 and ASTM A358 pipe specifications helps engineers and buyers select the most suitable stainless steel piping solution for their projects. Both standards offer excellent corrosion resistance and durability, but their manufacturing methods and application suitability differ significantly.