A276 vs. A479 Standards: Differences
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When sourcing stainless steel bars or forgings, engineers and buyers often encounter two commonly used ASTM specifications: A276 and A479. Both cover stainless steel bars, but they serve different purposes and industries.
So, what's the difference between ASTM A276 and A479, and when should each be used?
Technical Documentation Downloads
1. What is ASTM A276?
ASTM A276 covers stainless steel bars for general structural and mechanical use, including:
Cold-finished or hot-finished round bars, square bars, and flat bars
No requirement for pressure service
Includes grades like 304, 316, 410, 420, 416, etc.
Typical Uses:
Shafts, gears, bolts
Pump components
Aerospace and industrial parts
2. What is ASTM A479?
ASTM A479 applies to stainless steel bars and forgings used in pressure vessels, especially in ASME Section II applications.
Includes additional testing and heat treatment for safety in high-pressure environments
Can be dual-certified as A276/A479 if all requirements are met
Typical Uses:
Pressure vessel components
Boilers
Heat exchangers
Piping systems under pressure
Can A276 and A479 Be Used Interchangeably?
Not always. While chemically similar, A479 bars must meet stricter requirements for pressure use, including:
Mandatory solution annealing
Tensile testing
ASME boiler and pressure vessel code (BPVC) compliance
If your project involves high pressure, steam, or critical safety standards, you should specify ASTM A479.
Frequently Asked Questions (FAQ)
🔹 Is ASTM A479 suitable for pressure vessels?
Yes, it is specifically designed for stainless steel used in pressure-containing parts.
🔹 Is ASTM A276 used for boilers?
No, A276 is not qualified for pressure vessel or boiler use.
🔹 Are A276 and A479 chemically the same?
Often yes, but A479 requires additional mechanical properties and testing for pressure applications.
🔹 Can I substitute A479 for A276?
Yes, in many cases. But not the other way around-A276 should not be used in place of A479 in pressure systems.
