What are the grades of API 5L PSL1 pipeline steel?

API Spec 5L PSL1 pipeline steel is a high-strength and low-alloy steel, which can be used to produce various pipe fittings and pipes for oil and natural gas pipeline systems. It is the pipeline steel specification defined by the American Petroleum Institute (API), where PSL1 is a part of API 5L series pipeline steel and represents the standard grade. The grades under API 5L PSL1 pipeline steel standard are:

Class I grade:
L210: carbon steel, low carbon alloy steel, carbon content ≤ 0.21, silicon content ≤ 0.03, average thickness ≤ 25mm
L245: carbon steel, low carbon alloy steel, carbon content ≤ 0.24, silicon content ≤ 0.03, average thickness ≤ 25mm
L290: carbon steel, low carbon alloy steel, carbon content ≤ 0.29, silicon content ≤ 0.03, average thickness ≤ 25mm
L320: carbon steel, low carbon alloy steel, carbon content ≤ 0.32, silicon content ≤ 0.03, average thickness ≤ 25mm
L360: carbon steel, low carbon alloy steel, carbon content ≤ 0.36, silicon content ≤ 0.03, average thickness ≤ 25mm
L390: carbon steel, low carbon alloy steel, carbon content ≤ 0.39, silicon content ≤ 0.03, average thickness ≤ 25mm
L415: carbon steel, low carbon alloy steel, carbon content ≤ 0.41, silicon content ≤ 0.03, average thickness ≤ 25mm
L450: carbon steel, low carbon alloy steel, carbon content ≤ 0.45, silicon content ≤ 0.03, average thickness ≤ 25mm
L485: carbon steel, low carbon alloy steel, carbon content ≤ 0.48, silicon content ≤ 0.03, average thickness ≤ 25mm
L555: carbon steel, low carbon alloy steel, carbon content ≤ 0.55, silicon content ≤ 0.03, average thickness ≤ 25mm

Secondary grade:
Grade B: Carbon content ≤ 0.17, silicon content ≤ 0.03, average thickness ≤ 25mm
X42: carbon content ≤ 0.28, silicon content ≤ 0.03, average thickness ≤ 25mm
X46: carbon content ≤ 0.31, silicon content ≤ 0.03, average thickness ≤ 25mm
X52: carbon content ≤ 0.37, silicon content ≤ 0.03, average thickness ≤ 25mm
X56: carbon content ≤ 0.40, silicon content ≤ 0.03, average thickness ≤ 25mm
X60: carbon content ≤ 0.43, silicon content ≤ 0.03, average thickness ≤ 25mm
X65: carbon content ≤ 0.45, silicon content ≤ 0.03, average thickness ≤ 25mm
X70: carbon content ≤ 0.50, silicon content ≤ 0.03, average thickness ≤ 25mm
X80: carbon content ≤ 0.55, silicon content ≤ 0.03, average thickness ≤ 25mm

The grades of API 5L PSL1 pipeline steel can meet the needs of different users according to the carbon content and thickness. In addition, its low carbon content can improve the toughness and plasticity of steel, which is more conducive to pipeline processing and use. The grades under API 5L PSL1 pipeline steel standard can be applied to various industrial pipelines, such as oil, natural gas, gas, chemical industry, automobile, urban pipe network, etc. It is a good pipeline steel.