API 5L X56 Pipe

API 5L X56 is a carbon steel specified for liquid and gas transportation pipes. The applications are usually found in the oil and gas industries. These pipes can be seamless or welded. There are manganese, sulfur and silicon in the composition in addition to the carbon and iron core materials. There are two different product specification levels in API 5L X56. The API 5L X56 PSL2 has additional NDE, notch toughness and mandatory requirements than the API 5L X56 PSL1. The PSL1 is the most commonly used; however, the PSL2 can also be interchangeably utilized in systems that use PSL1. This specification offers combination of minimum yield strength of 56000PSI and the minimum tensile strength of 71000PSI. The API 5L Grade X56 is produced in hot rolled, seamless or welded conditions. The dimensions vary depending on the need of any application. There are wall thicknesses up to 250mm in API 5L X56 Grade B correlating to schedules 20 through XXS which in turn indicate the pressure containment capacities. Hydrogen embrittlement is greatly reduced with HIC Tested X56 and is marked by ISO 3183 L390 Grade X56. The pipes could be coated differently and can be delivered with different delivery conditions such as rolled or thermodynamically rolled.

Standard Specification of Grade B X56 Linepipe


Seamless/ SAW/ ERW / LSAW / DSAW

2" to 24" O.D.


Wall Thickness

Schedule 10 to 160, STD, XS, XXS


Pipe End

Plain, Bevelled

Standard and Dimensions
Trade Name API SPEC 5L ISO 3183 PSL1 / PSL2 X56, ASTM A106/ A53/ A333 Grade 6/ API 5L GR.B X56
Common Standards EN10296, GB/T14975, ASTM A333/A333M, GB/T9711 ASTM, GB/T14976, GB13296-91, ASTM A106/A106M, API 5CT, ASTM A53/A53M, ASTM A139, 5L, ISO3183, ANSI/API ASME B36.10, GB/T3091, GB9948
API Spec PSL Level
  • Grade A25 X56 PSL1
  • Grade B X56 PSL2
Pipe End Forming
  • X56 PSL1 : Plain, threaded, special coupling pipe, bevelled
  • X56 PSL2 : Plain-end
PSL1 Grade
  • Grade A
  • Grade B
Length 6-12 meters
Regular inspection and testing TM0177, SSC, NACE MR0175, HIC, IBR, CVN impact, TM0284, H2 SERVICE, DWT, Hardness
Steel material
Material Origins Ukraine, Japanese, Korean, Russian, US, European, Indian
Mill Test Certificate (MTC) EN 10204/3.1B

API 5L X56 Different Types

API 5l X56 PSL2

API 5l X56 PSL2

High Yield / Hsaw / Helical Steel Pipe.

X56 Grade Casing

X56 Grade Casing

Saw / Dsaw Fluid Pipe, Sour Service Line Pipes

API 5l X56m PSL2

API 5l X56m PSL2

Welded and Seamless Steel Line Pipe, Bend Pipe

What the difference is between X56 & X56M PSL2 Pipe?

Grade Letter Delivery Condition
X56M "M" letter means Thermomechanical rolled or thermomechanical formed

Why mark "Q" on X56Q PSL2 Pipe?

Grade Letter Delivery Condition
X56Q "Q" letter means Quenched and tempered

Meaning of "N" on X56N PSL2 marked Pipe

Grade Letter Delivery Condition
X56N "N" letter means normalized or normalized and tempered, Normalizing rolled, normalizing formed

USC Unit for X56 Pipe

ISO 3183 L390 pipe / L390Q / L390N / L390M

Grade X56 Pipeline is Repairable or Not

API5L X56 PSL1 allowed to repair by welding if the purchaser and the manufacturer are agree but PSL2 shall not be repaired by welding.

API 5L X56 Pipe Surface protection coating

API 5L X56 Pipe Surface protection coating

X56 PSL2 Pipeline Equivalent Material

X56 PSL1 L390
X56 PSL2 L390N / X56N
L390Q / X56Q
L390M / X56M

X56 Carbon Steel Pipe Composition

Gr. C maximum Mn maximum P S maximum V maximum Nb maximum Ti maximum
min max
B 0.28 1.2 - 0.03 0.03 c.d c,d d
X56 0.28 1.4 - 0.03 0.03 d d d

Grade B X56 Mechanical Analysis

PSL 1 X56
API Yield Stress Mpa Tensile StrengtStressh Mpa Elongation
B 245 415 c
X56 390 490 c
PSL 2 X56
Gr. Yield Stress Mpa Tensile Stress Mpa Raito Elongation
minimum maximum minimum maximum maximum minimum
BN 245 450 415 655 0.93 f
X56N 390 545 490 760 0.93 f

API 5L X56 Temperature Ratings

Hot-coated Grade with epoxy powder Temperature
X56 200°C

X56 PSL1/2 Pressure Flow Rating Chart

Grade PSI
X56 56000 Psi

Application of API 5L X56 Pipe Material

  • Crude oil and gasoline transmissions
  • To safely hold liquid petroleum products
  • Liquid petroleum
  • Storing petroleum liquid
API 5L X56 Pipe Material Application
  • The base materials are Ingots, billets, blooms, coils or plates to produce pipelines. Killed and melted steel is preferable for PSL2.

Carbon Steel Grade X56 Linepipes are suitable to transport oil and gas fluids and liquids for over long distances.