ASTM F899 420A Martensitic Wrought Stainless Steels

What are 420A Stainless Steels? 420A is the second martensite grade steel with higher hardness than the primary 410 stainless steels defined in the standard. This can be hardened afterwards by heat treatment, this has got more Carbon than the 410 type of stainless steel.

Dimensional Characteristics of 420A Stainless Steels: The applicable thickness in millimeters for this 420A Stainless Steels ranges from 0.25 to 4 whereas the width in millimeters is from 600 to 1200. Moreover outer diameter of pipe in inches ranges from 0.5 to 8. In the case of rod the diameter in inches is from 1 to 8.

Available Forms in Market: Following are the available forms of 420A Stainless Steels:

• Sheets
• Round Bar
• Forgings
• Pipes

The Chemical Composition of 420A Stainless Steels: Chemical alloying compositions are explicated below

• Maximum percentage of Carbon as defined in the standard is 0.25 whereas Minimum percentage of Carbon as defined in the standard is 0.16
• Maximum percentage of Manganese as defined in the standard is 1
• Maximum percentage of Phosphorus as defined in the standard is 0.04
• Maximum percentage of Sulphur as defined in the standard is 0.03
• Maximum percentage of Silicon as defined in the standard is 1
• Maximum percentage of Nickel as defined in the standard is 1
• Maximum percentage of Chromium as defined in the standard is 14 whereas Minimum percentage of Chromium as defined in the standard is 12

Crux: Other mechanical properties of this type of steel & its family is highly maneuvered by heat treatment methods and therefore not specifically defined. Since the standard also share a generic view therefore in this writeup it reflects the same. More details can be sought in comments section.

Mechanical Properties of 420A Stainless Steels: Mechanical properties are as under

• Hardness in HRC as specified in the standard is from 48 to 53.
• Tensile strength is not defined in the standard.
• Yield strength is not defined in the standard.
• Elongation is not defined in the standard.

Equivalent Materials of 420A Stainless Steels: The equivalent materials for 420A Stainless Steels specified in other recognized standards are listed as under

• In JIS standard, the equivalent material is referred as 420J1 type steel.
• In DIN standard, the equivalent material is referred as 1.4021 type steel.
• In ISO standard, the equivalent material is referred as 420A type steel.

Industrial Applications of 420A Stainless Steels: These are used in variety of industrial applications including

• Shear blades
• Needle valves
• Surgical Instruments
• Cutlery
• Shearing devices

Note: These values are indicative and for information purpose only. Some of the given information can be outdated. There are also minor possibilities for inaccuracies in the text due to human error. For inaccuracies & outdated text you can e-mail & inform the Content Manager at materialgrades@yahoo.com