US steel products are with more standards, mainly in the following categories:

ANSI–American National Standard

AISI–American Society of Iron and Steel Standards

ASTM–American Society for Testing and Materials

ASME–American Society of Mechanical Engineers

AMS–Aerospace material specifications (one of the most commonly used materials specifications in the US aviation industry, developed by SAE)

API–American Petroleum Institute standards

AWS–American Welding Association Standard

SAE–American Society of Automotive Engineers Standards

MIL–US military standards

Qq–US federal government standards

API–American Petroleum Institute standards

ANSI–American National Standard

ASME–American Society of Mechanical Engineers

ASTM–American Society for Testing and Materials

These standards, all belong to the US  steel standard, such as ASME in the material used by the standards are from ASTM, the valve in the standard reference API, and mild steel pipe fittings from the ANSI standard. The difference lies in the different focus of the industry, so the adoption of different standards. API, ASTM, ASME are members of ANSI. American National Standards Institute standards, the vast majority from the professional standards. On the other hand, the professional associations, associations, groups can also be based on existing national standards to develop certain product standards. Of course, can not follow the national standard to develop their own association standards. ANSI standards are voluntary. The United States believes that mandatory standards may limit productivity gains. But by the law and the government departments to develop standards, generally a mandatory standard.