What does 1008/1010 mean?

• SAE International (formerly Society of Automotive Engineers) is a professional association and standards developing organization in various disciplines.
• J403 is the SAE standard which governs the chemical composition of SAE Carbon Steels, including the grades 1008 and 1010.

• It is very common for some users to specify 1008/1010 but this is, at the very least, confusing. As can be seen from the above table there is an overlap in the required chemical composition of 1008 and 1010 but they are not the same thing.  

Are 1010 and CS Type B the same?

• 1010 is a low carbon grade specified in SAE J403 to have the chemical composition shown above.
• CS Type B is a low carbon grade specified by ASTM (formerly American Standards for Testing and Materials) in various product standards (e.g. A653 for Galvanized or Galvanneled, A1008 for Cold Rolled, A792 for 55% Aluminum-Zinc Alloy-Coated, A1011 for Hot Rolled).
• More often than not, a 1010 is a subset of CS Type B, i.e. 1010 will generally meet CS Type B but not vice versa.  However, there are differences between the two grades in terms of requirements governing residual elements so a detailed review is required in order ensure a successful cross application.

What is the difference between 1018, 1020, 1021 and 1022 and what are the mechanical properties of these grades?

• 1018, 1020, 1021 and 1022 are grades specified in SAE J403 that are commonly referred to as mid-carbon grades.

• As can be seen from the above table there are overlaps between 1018, 1021 and 1022.  However these three grades can be quite different from each other depending on where in the allowable chemical composition range the steel mill aims to produce and because there are unique allowances for residual elements and additional elements in J403.
• These grades are often ordered with the expectation of meeting certain mechanical properties, e.g. 50 KSI minimum yield strength.  Care must be taken to ensure that the applied chemical composition is compatible with the mechanical properties required.

What are 44W and 50W?

• Canadian Standards Association (operating as “CSA Group”) is a Canadian organization which develops standards globally in multiple areas.
• 44W and 50W are two common grade designations under CSA G40.20/G40.21: General Requirements for Rolled or Welded Structural Quality Steel/Structural Quality Steel.
• These grades have chemical and mechanical property requirements similar to some in ASTM standards (e.g. in ASTM A1018 Structural Steels and High Strength Low Alloy Steels) but this CSA standard is intended for discrete lengths, either produced as plate or cut from coil.  As such 44W and 50W require test certification from the body of a coil if produced this way.
• Often the mid-carbon grades identified under SAE J403 will meet both the chemical and mechanical requirements of CSA G40.20/G40.21 but, due to differences between the standards, compliance to specification must be ensured by reading “the fine print”.