API 5L X42 pipe (L290 pipe according to ISO 3183) is labeled by its minimum yield strength, 42100 Psi or 290 Mpa. 

It is a greater category than Grade B and is a low-medium grade pipe. The API 5L X42 pipes are needed in substantial quantities for most pipelines for oil and gas transmissions due to their efficient features and functions.

Product Description

X42 Pipes are the kind that is wielded for transmitting oil and gas materials over long expanses. 

The 5L X42 variety is one of the multiple qualities that are convenient within this criteria. The American Petroleum Institute regulates and oversees the material levels, grades, and significant sizes of the X42 products. 

The equipment can differ based on the mechanical features needed by the line pipes. While High-temperature actions expect greater mechanical characteristics, the low-temperature works can utilize lower-grade-grade API 5L X42 Seamless Pipe varieties.

Chemical Composition

The chemical properties and composition of the two categories of API 5L X42 are different in a few ways. Here, a summary of the chemical composition of both kinds is given. 

Chemical Composition for API 5L X42 PSL1 (Seamless Pipes)

Steel TypeMass Fraction According to the Heat and Product Estimation (%)
L290 or X420.28 (Maximumb)0.030 (Maximum)c, d (Maximum)1.30 (Maximumb)c, d (Maximum)0.030 (Maximum)d (Maximum)

Chemical Composition for API 5L X42 PSL1 (Welded Pipes)

SteelTypeMass Fraction According to the Heat and Product Estimation (%)
L290 or X420.26 (Maximumb)0.030 (Maximum)c,d (Maximum)1.30 (Maximumb)c, d(Maximum)0.030(Maximum)d(Maximum)

The given specifications for API 5L X42 are based on the properties of PLS1. For API 5L X 42 PSL2, the chemical composition is more severe than PSL1.

Chemical Composition for API 5L X42 PSL2 (Seamless Pipes)

Steel TypeMass Fraction According to the Heat and Product Estimation (%)Carbon Equivalent (% Max)
L290R or X42R0., l0.430.25
L290N or X42N0., l0.430.25
L290Q or X42Q0.240.151.400.050.450.050.050.025e, l0.430.25

Chemical Composition for API 5L X42 PSL2 (Welded Pipes)

Steel TypeMass Fraction According to the Heat and Product Estimation (%)Carbon Equivalent (% Max)
L290M or X42M0.220.0151.200.040.450.050.050.025e, l0.430.25

Mechanical Properties

The mechanical properties of  API 5L X42 are based on its yield strength and tensile strength. It is the same for both seamless and welded pipes.

Pipe TypeSeamless and Welded Pipe BodiesWeld Seam of EW, LW
Yield Strength a(Minimum)Tensile Strength a(Minimum)Elongation(Minimum)Tensile Strength b  (Minimum)
L290 or X42290 (42,100 psi)415 (60,200 psi)c415 (60,200 psi)

The API 5L X42 seamless pipes are manufactured with exceptional mechanical aspects. They retain a tensile strength of at least 60,200 psi and a minimum yield strength of 42,100 psi. 

The API 5L X42 welded pipes are developed when parts of steel are fused with a filler. These pipes are exceptionally low maintenance and have excellent durability. This category of pipes can last and function for a very long time.

Equivalent Designation

The material equivalents for both API 5L X42 PSL1 and API 5L X42 PLS2 are summarized in the given chart.

Material Type/GradeAPI 5L X42 PLS1L290 or X42
Material Type/GradeAPI 5L X42 PLS2L290M or X42ML290N or X42NL290Q or X42QL290R or X42R

Specifications for API 5L X42

The specification related to  API 5L X42 encompasses both seamless and welded categories of pipes - for both  API 5L X42 PSL1 as well as  API 5L X42 PSL2.

The API 5L X42 PSL1 Pipe is characterized by lower mechanical aspects, making it less expensive and more accessible. For that reason, the PSL1 variety is more frequently used.

The API 5L X42, PSL2, is assigned for works and applications that need more mechanical properties like resistance to high corrosion, high-pressure control, and tolerance for high temperature.

The places where these categories of API 5L X42 are used include industries and businesses such as household water supply, liquid and gas pipelines, and natural gas processing plants. All of these enterprises operate with both of these kinds of pipes as per the situation and circumstances required.


The range of applications for API 5L X42 pipe is wide and varied in range. Devices and industries that use these pipes include oil refineries, pressure vessels, power generators, sugar production, boiler appliances, steel trades, and fluid and gas transmission pipes. 


An account of the specifications of the API 5L X42 category of pipes is given here, along with its relevance and utility in the services related to corrosive and non-corrosive liquids and gas transmission.

Based on the durability, agenda, and functional prerequisites, API 5L X42 pipes are produced in numerous grades. The use of this category of pipes in both national and international trade and commerce is vast. With all the proper functional uses, these pipes are relevant to a wide range of industries in both onshore as well as offshore services.