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Chemical compositions of AISI (ASTM/ASME) and UNS heat resisting stainless steel grades

Introduction – AISI ASTM ASME and UNS

Most ASTM and ASME standards list the steel grades by their UNS, (Unified Numbering system), numbers, but also make reference, where appropriate to the more general AISI, (American Iron and Steel Institute), grade designations. These grade numbering systems are widely used in the USA, where they originated and are recognised by most stainless steel specifiers and users.
The American Iron and Steel Institute, (AISI), developed designations such as 309, 310 etc. and published compositions for these in their ‘Steel Products Manual’, (1974).
These are NOT specifications, but steel grade composition ranges only.
These grades were used by the American Society Testing and Materials, (ASTM), to identify grades in a wide range of standards they published for stainless products, such as sheets and plates, (ASTM A240), bars, (ASTM A276), and tubes, (ASTM A269).
The compositions of the AISI grades were made more specific with the introduction of the ‘Unified Numbering System’, jointly established by ASTM and SAE, (Society of Automotive Engineers).
This five digit number, preceded by the letter ‘S’ for most stainless steels, identified the specific variant of the grade

e.g. 309 being UNS S30900, 304H being UNS S30409

American Society of Mechanical Engineers, (ASME), publish design codes and standards for pressure applications. ASME standards are generally based on the appropriate ASTM standards, but the standard numbers are preceded with the letters ‘SA’, rather than just the ‘A’ of the ASTM standards.
Where UNS grade numbers are used, these are universal, regardless of the product type or the standard in which they appear.

The AISI designations have been adopted in Japan. The AISI number is preceded with the letters SUH for heat resisting grades e.g. SUH 310.
The composition ranges should always be checked in the appropriate standard.

Composition tables

The tables in this article use the UNS number as their key, but also show the related AISI and SAE numbers. Where appropriate, common names for the steels are also shown.
As an alternative to scanning down the list try the ‘find’ facility on your keyboard, using the ‘Ctrl’ and ‘F’ keys together. Type in the term you are looking for in the dialog box that then appears.
The data given is not intended to replace that shown in individual standards to which reference should always be made.

Heat resisting grades

Designation Chemical composition % by mass max unless stated
UNS No SAE No AISI No / Common Name C Si Mn P S Cr Mo Ni Others
S21500 – Esshete 1250 0.06/0.15 0.20/1.0 5.50/7.0 0.045 0.030 14.0/16.0 0.80/1.20 9.00/11.0 B 0.003/0.009; Nb 0.75/1.25; V 0.15/0.40
S30409 – 304H 0.04/0.10 0.75 2.00 0.045 0.030 18.0/20.0 – 8.0/10.5 –
S30415 – 153MA 0.04/0.06 1.00/2.00 0.80 0.045 0.030 18.0/19.0 – 9.0/10.0 N 0.12/0.18; Ce 0.03/0.08
S30451 – 304N 0.08 0.75 2.00 0.045 0.030 18.0/20.0 – 8.0/10.5 N 0.10/0.16
S30452 – 304HN (XM-21) 0.08 0.75 2.00 0.045 0.030 18.0/20.0 – 8.0/10.5 N 0.16/0.30
S30615 – RA85H 0.16/0.24 3.2/4.0 2.00 0.030 0.030 17.0/19.5 – 13.5/16.0 Al 0.80/1.50
S30815 – 253MA 0.05/0.10 1.40/2.00 0.80 0.040 0.030 20.0/22.0 – 10.0/12.0 N 0.14/0.20; Ce 0.03/0.08
S30900 30309 309 0.20 1.00 2.00 0.045 0.030 22.0/24.0 – 12.0/15.0 –
S30908 30309S 309S 0.08 0.75 2.00 0.045 0.030 22.0/24.0 – 12.0/15.0 –
S30909 – 309H 0.04/0.10 0.75 2.00 0.045 0.030 22.0/24.0 – 12.0/15.0 –
S30940 – 309Cb 0.08 0.75 2.00 0.045 0.030 22.0/24.0 – 12.0/16.0 Nb 10xC / 1.10
S30941 – 309HCb 0.04/0.10 0.75 2.00 0.045 0.030 22.0/24.0 – 12.0/16.0 Nb 10xC / 1.10
S31000 30310 310 0.25 1.50 2.00 0.045 0.030 24.0/26.0 – 19.0/22.0 –
S31008 30310S 310S 0.08 1.50 2.00 0.045 0.030 24.0/26.0 – 19.0/22.0 –
S31009 – 310H 0.04/0.10 0.75 2.00 0.045 0.030 24.0/26.0 – 19.0/22.0 –
S31040 – 310Cb 0.08 1.50 2.00 0.045 0.030 24.0/26.0 – 19.0/22.0 Nb 10xC / 1.10
S31041 – 310HCb 0.04/0.10 0.75 2.00 0.045 0.030 24.0/26.0 – 19.0/22.0 Nb 10xC / 1.10
S31400 30314 314 0.25 1.50/3.00 2.00 0.045 0.030 23.0/26.0 – 19.0/22.0 –
S31609 – 316H 0.04/0.10 0.75 2.00 0.045 0.030 16.0/18.0 2.00/3.00 10.0/14.0 –
S31651 – 316N 0.08 0.75 2.00 0.045 0.030 16.0/18.0 2.00/3.00 10.0/14.0 N 0.10/0.16
S32109 – 321H 0.04/0.10 0.75 2.00 0.045 0.030 17.0/19.0 – 9.0/12.0 Ti 4x(C+N) / 0.70
S33228 – – 0.04/0.08 0.30 1.00 0.020 0.015 26.0/28.0 – 31.0/33.0 Al 0.025;Ce 0.05/0.10; Nb 0.6/1.0
S33400 – 334 0.08 1.00 1.00 0.030 0.015 18.0/22.0 – 19.0/21.0 Al 0.15/0.60; Ti 0.15/0.60
S34709 – 347H 0.04/0.10 0.75 2.00 0.045 0.030 17.0/19.0 – 9.0/13.0 Nb 8xC /1.00
S34800 – 348 0.08 0.75 2.00 0.045 0.030 17.0/19.0 – 9.0/13.0 Nb+Ta 10xC / 1.00; Ta 0.10; Co 0.20
S34809 – 348H 0.04/0.10 0.75 2.00 0.045 0.030 17.0/19.0 – 9.0/13.0 Nb+Ta 10xC /1.00; Ta 0.10; Co 0.20
S35045 – – 0.06/0.10 1.00 1.50 0.045 0.015 25.0/29.0 – 32.0/37.0 Al 0.15/0.60; Ti 0.15/0.60
S35315 – 353MA 0.04/0.08 1.20/2.00 2.00 0.040 0.030 24.0/26.0 – 34.0/36.0 N 0.12/0.18; Ce 0.03/0.10
S41041 – – 0.13/0.18 0.50 0.40/0.60 0.030 0.030 11.50/13.00 0.20 0.50 Al 0.05; Nb 0.15
S41425 – – 0.05 0.50 0.50/1.00 0.020 0.005 12.0/15.0 1.50/2.00 4.0/7.0 N 0.06/0.12; Cu 0.30
S41800 – Greek Ascoloy (615) 0.15/0.20 0.50 0.50 0.040 0.030 12.00/14.00 0.50 1.80/2.20 W 2.50/3.50
S42200 – 616 0.20/0.25 0.50 0.50/1.00 0.025 0.025 11.0/12.5 0.90/1.25 0.50/1.00 V 0.20/0.30; W 0.90/1.25
S42300 – Lapelloy (619) 0.27/0.32 0.50 0.95/1.35 0.025 0.025 11.00/12.00 2.50/3.00 0.50 V 0.20/0.30
S44300 – MT443 0.20 1.00 1.00 0.040 0.030 18.0/23.0 – 0.50 Cu 0.90/1.25
S44600 51446 446 0.20 1.00 1.50 0.040 0.030 23.0/27.0 – 0.75 N 0.25
S64152 – XM-32 0.08/0.15 0.35 0.50/0.90 0.025 0.025 11.00/12.50 1.50/2.00 2.00/3.00 N 0.01/0.05; V 0.25/0.40
N08800 – 800 (332) 0.10 1.00 1.50 0.045 0.015 19.0/23.0 – 30.0/35.0 Fe 39.5 min; Al 0.15/0.60; Ti 0.15/0.60
N08810 – 800H 0.05/0.10 1.00 1.50 0.045 0.015 19.0/23.0 30.0/35.0 30.0/35.0 Cu 0.75; Fe 39.5 min; Al 0.15/0.60; Ti 0.15/0.60
N08811 – – 0.06/0.10 1.00 1.50 0.040 0.015 19.0/23.0 – 30.0/35.0 Cu 0.75; Fe 39.5 min; Al 0.15/0.60; Ti 0.15/0.60

Related Articles

  1. Related heat resisting stainless steel grades

Related References

  1. ASTM and SAE-AMS Standards and Specifications for Stainless Steel
  2. ASTM International, West Conshohocken, PA 19428-2959, USA, 2003

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