Type 201 stainless steel is the ASTM-style grade designation for UNS S20100, a chromium-manganese-nickel austenitic stainless steel. In ASTM product standards, the word “Type” is used alongside numerical grade names such as Type 201 and Type 304. For flat products, ASTM A240/A240M covers chromium, chromium-nickel, and chromium-manganese-nickel stainless steel plate, sheet, and strip, while ASTM A666/A666M covers annealed or cold-worked austenitic stainless sheet, strip, plate, and flat bar. :contentReference[oaicite:0]{index=0}

Type 201: What the ASTM “Type” Means

“Type 201” is not merely a supplier nickname. It is a formal grade designation used in ASTM material tables, in the same general naming family as Type 301, Type 304, Type 316, and other stainless grades. The corresponding UNS designation is S20100.

For a sheet or plate inquiry, however, “Type 201” should normally be connected to the applicable product specification. A complete description can therefore be written as Type 201, UNS S20100, ASTM A240/A240M when A240 is the governing product standard.

Type 201 Stainless Steel Data Card

Type 201 is designed as a lower-nickel austenitic stainless steel. Manganese and nitrogen are used as important parts of its alloy design. The following composition ranges are the commonly specified ASTM A240 values for S20100.

ASTM A240/A240M specifically includes chromium-manganese-nickel stainless steels within its scope and requires the material to meet specified chemical and mechanical requirements. :contentReference[oaicite:1]{index=1}

ASTM A240 Mechanical Data for Type 201

The ASTM A240 table distinguishes two Type 201 strength rows for S20100, identified as 201-1 and 201-2. This is important because “Type 201” does not always mean one single mechanical-property line. The required condition should therefore be confirmed in the purchase order.

The two rows are why a simple statement such as “Type 201 = 655 MPa tensile strength” can be misleading. The applicable ASTM table, product condition, and ordered requirement should be checked before a value is used for design or inspection. ASTM's published material tables distinguish these S20100 rows. :contentReference[oaicite:2]{index=2}

Where Type 201 Appears in ASTM Tables

The “Type” column is positioned alongside the UNS designation in ASTM stainless steel tables. This allows the grade to be identified in two complementary ways: the traditional type designation and the unified numerical designation.

This table structure is the reason “Type 201” is more meaningful than a generic “201 stainless” label. It can be traced to a defined grade entry and then connected to the applicable product specification.

Type 201 vs Type 201L vs Type 201LN

These designations should not be treated as three spellings of the same material. 201L is a low-carbon modification of Type 201, while 201LN combines low carbon with controlled nitrogen and is designed for higher strength and improved low-temperature performance. ASTM tables list corresponding low-carbon and nitrogen-modified 201 grades separately. :contentReference[oaicite:3]{index=3}

For example, an ASTM-based data sheet for 201LN shows a much lower carbon limit and controlled nitrogen addition than the standard Type 201 composition, while retaining the broader Type 201 alloy family. :contentReference[oaicite:4]{index=4}

Why the “L” Matters

The L in 201L indicates a low-carbon modification. Lower carbon reduces the tendency toward chromium-carbide precipitation during welding and can improve resistance to weld-related sensitization.

Why the “LN” Matters

The LN designation indicates a low-carbon, nitrogen-containing modification. Nitrogen contributes to austenite stability and strength. 201LN has been developed for applications where higher strength and low-temperature toughness are important. :contentReference[oaicite:5]{index=5}

Type 201 vs 201L vs 201LN: Quick Mechanical View

ASTM A240 tables demonstrate that these grades can have different minimum mechanical requirements. The figures below are useful for understanding the grade separation, but the exact edition and product condition should always be checked against the purchase order.

These ASTM table entries illustrate why the suffix cannot be ignored. A drawing that specifies 201LN is not asking for generic 201 stainless steel, even though the grades belong to the same alloy family. :contentReference[oaicite:6]{index=6}

How to Write Type 201 on a Drawing

Writing only “Type 201” can identify the alloy but may leave the product specification unclear. A better engineering note connects the type designation with the ASTM product standard.

ASTM A240 covers plate, sheet, and strip, so it is an appropriate product specification when those forms are being ordered under its scope. ASTM A666 is another relevant specification for annealed or cold-worked austenitic stainless sheet, strip, plate, and flat bar. The correct standard should therefore follow the actual product and application. :contentReference[oaicite:7]{index=7}

Do Not Confuse Grade Name With Product Standard

A common purchasing error is to write “ASTM 201” as though 201 were itself the complete ASTM specification. ASTM uses Type 201 as a grade designation, while specifications such as A240/A240M or A666/A666M establish requirements for particular product forms.

Type 201 Stainless Steel: Procurement Checklist

For an engineering drawing or purchase order, the following information provides a much safer identification than “201 stainless” alone.

Type 201 Stainless Steel Sourcing

Teda Ganghua can support B2B sourcing of Type 201 stainless steel according to the required grade, ASTM product specification, dimensions, surface condition, supply form, and inspection documents. This is useful when a drawing says “Type 201” but the quotation must be converted into a complete commercial specification.

For a quotation, buyers can provide the drawing or material note together with the required thickness, width, length or coil size, finish, quantity, and certificate requirements. The grade can then be matched with the appropriate product specification before production. Explore the available stainless steel products for Type 201 and other stainless grades.

FAQ: Type 201 Stainless Steel

Is Type 201 an ASTM stainless steel grade?

Yes. Type 201 is used as a formal grade designation in ASTM stainless steel tables and corresponds to UNS S20100. The applicable ASTM product specification must still be stated separately.

What ASTM standard is used for Type 201 sheet?

ASTM A240/A240M is a major product specification for stainless steel plate, sheet, and strip and includes chromium-manganese-nickel grades. ASTM A666/A666M is also relevant to annealed or cold-worked austenitic stainless sheet, strip, plate, and flat bar. The correct standard depends on the product and application.

What is the difference between Type 201 and 201L?

201L is a low-carbon modification of Type 201. The lower carbon level is intended to improve resistance to sensitization associated with welding. It should therefore be ordered as its own grade rather than treated as ordinary Type 201.

What is Type 201LN?

201LN is a low-carbon, nitrogen-modified member of the 201 family. Nitrogen contributes to austenite stability and strength, and the grade is used where higher strength and low-temperature performance are important.

How should Type 201 be written on a drawing?

A practical notation is Type 201, UNS S20100, ASTM A240/A240M when A240 is the applicable product specification. Add product form, dimensions, surface finish, condition, and inspection requirements to make the drawing or purchase order complete.