What is ASTM?
ASTM is the common designation for the ASTM International (formerly known as American Society for Testing and Materials). ASTM International is an American based standard organisation that oversees the development and curation of technical standards. One of these technical standards is A479.
What is A479?
The ASTM A479 (A479M is the equivalent metric version of A479) is a technical document a that outlines the requirements for stainless steel hot/cold finished bars. Bars with various forms such as: rounds, squares, and hexagons, and hot-rolled or extruded shapes such as angles, tees, and channels. These stainless-steel forms are targeted for use in boiler and pressure vessels. The specification covers four categories of steels austenitic, austenitic-ferritic, ferritic, and martensitic. Contained within A479 are the specified tensile strength, yield strength, elongation, and hardness values for various heat treatments (normalized, tempered, annealed, and quenched). A special note for the heat treatments and additional corrosion tests for the austenitic stainless are also provided in A479. Steel grades for A479 are defined by their chemical composition. ASTM A479 equivalent materials in other standards may be found by investigating the individual material grades.
Material Grades of A479
There are three common grade naming conventions for A479:
1.Three Number Code:
3XX - Austenitic Chromium Nickel Alloys
4XX - Ferritic / Martensitic Chromium Alloys
Additional Letters are related to added elements.
Ti – Titanium
H – Higher Carbon
L – Lower carbon
N – Nitrogen
2. Unified Numbering System (UNS)
A – Primary material category letter S for steel or N for Nickel.
X – Unique Number code for category.
3. ASTM numbering system for proprietary steels.
XM - Z
Z - Code for steel grade.
See material pages of the steel grades of ASTM A108 for greater details on the material properties (chemical composition, mechanical strength) and equivalent materials:
|TW Metals||USA, UK, Italy, Mexico, India, Poland|
|Progressive Alloy Steels Unlimited||USA|
|Best Stainless & Alloys||USA|
|Alloy Wire International||Australia|
|Langley Alloys Limited||UK|
|Stainless Structurals||USA, Switzerland, Singapore|
|Titanium Industries, Inc. (T.I.)||USA|
|National Specialty Alloys||USA, Mexico|