Introduction to the ASTM Designation System

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Overview of ASTM Specifications

ASTM specifications represent a consensus among producers, specifiers, fabricators, and users of steel mill products. These standards classify, evaluate, and specify the material, chemical, mechanical, and metallurgical properties of different types of steels used in mechanical components, industrial parts, and construction elements.

ASTM Designation System for Metals

ASTM’s designation system for metals consists of a letter followed by a sequentially assigned number. The letter "A" is used for ferrous materials. Metric ASTM standards have a suffix letter "M".

Example: ASTM A 582/A 582M-95b (2000), Grade 303Se-Free-Machining Stainless Steel Bars

• A: Describes a ferrous metal.
• 582: A sequential number without any relationship to the metal’s properties.
• M: Indicates the standard is written in rationalized SI units.
• 95: Indicates the year of adoption or last revision.
• b: Indicates the third revision of the standard in 1995.
• (2000): Indicates the year of last re-approval.
• Grade 303Se: Indicates the grade of steel with a selenium addition.

 

Key Uses of ASTM Specifications

ASTM standards are widely used in the steel industry and have often been adopted by the American Society of Mechanical Engineers (ASME) with minimal modifications. ASME uses the prefix "S" followed by the ASTM designation (e.g., ASME-SA213 is identical to ASTM A 213).

Definitions: Grade, Type, and Class

Within the steel industry:

• Grade: Describes chemical composition.
• Type: Defines the deoxidation practice.
• Class: Indicates other characteristics like strength level or surface finish.

However, within ASTM standards, these terms are used more loosely to identify specific metals within a standard.

 

Example 1: ASTM A 106-02a, Grades A, B, C - Seamless Carbon Steel Pipe for High-Temperature Service

• Grade A: 0.25% C (max), 48 ksi tensile strength (min)
• Grade B: 0.30% C (max), 60 ksi tensile strength (min)
• Grade C: 0.35% C (max), 70 ksi tensile strength (min)

 

Example 2: ASTM A 276-03, Types 304, 316, 410 - Stainless and Heat Resisting Steel Bars and Shapes

• Types based on the SAE designation system for stainless steels.

 

ASTM Grade Designators in Pipes, Tubes, and Forgings

Different letters are used for various products:

• P: Pipe
• T: Tube
• TP: Tube or Pipe
• F: Forging

 

Examples:

• ASTM A 335/A335-03, Grade P22: Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service
• ASTM A 213/A213M-03a, Grade T22: Seamless Ferritic and Austenitic Alloy Steel Boiler, Superheater, and Heat-Exchanger Tubes
• ASTM A 312/A312M-03, Grade TP304: Seamless and Welded Austenitic Stainless Steel Pipe
• ASTM A 336/A336M-03a, Class F22: Steel Forgings, Alloy, for Pressure and High-Temperature Parts

 

View Groups of ASTM Standards

For detailed information, click on the following links to view groups of ASTM standards:

• Iron, Nickel Alloy/Heat Resistant Nickel Alloys and High Silicon Steel
• Structural and Constructional Steels: Part One
• Structural and Constructional Steels: Part Two
• Structural and Constructional Steels: Part Three
• Structural and Constructional Steels: Part Four
• Structural and Constructional Steels: Part Five
• Stainless Steels
• Castings
• Forgings, Welding and Filler Materials, Powder Metallurgy
• Coated Steels
• Ferro Alloys, Others and Terms/Definitions
• Testing / Determination