API 5L Line Pipe

API 5L Line Pipe Physical Properties

API 5L Line Pipe grade designations come from API Spec 5L Specification for API 5L Line Pipe. Standard API 5L Line Pipe has grade designation A and B. Stronger grades have the designation X followed by the specified minimum yield strength of the pipe steel, measured in kilopounds per square inch (abbreviated ksi), e.g. X60 for pipe having a minimum yield strength of 60 ksi. See the table below for the standard available grades.

API 5L Line Pipe Physical Properties

API 5L Grade	Yield Strength min. (ksi)	Tensile Strength min. (ksi)	Yield to Tensile Ratio (max.)	Elongation min. %¹
A	30	48	0.93	28
B	35	60	0.93	23
X42	42	60	0.93	23
X46	46	63	0.93	22
X52	52	66	0.93	21
X56	56	71	0.93	19
X60	60	75	0.93	19
X65	65	77	0.93	18
X70	70	82	0.93	17
X80	80	90	0.93	16

API 5L Line Pipe mechanical testing usually omits Reduction of Area (RA) measurement reporting, and Charpy V-Notch (CVN Impact Test) testing. This prevents use of this pipe as body material above 36 ksi yield strength for API Spec 6Aequipment without retesting for Reduction of Area, and in the case of low temperature service, Charpy V-Notch testing as well.

API 5L Line Pipe Chemical Properties

Steel grade (Steel name)	Mass fraction, based upon heat and product analyses, %
	C	Mn	P		S	V	Nb	Ti
	max	max	min	max	max	max	max	max
Welded pipe
L245 or B	0,26	1,20	–	0,030	0,030	c,d	c,d	d

L290 or X42	0,26	1,30	–	0,030	0,030	d	d	d

L320 or X46	0,26	1,40	–	0,030	0,030	d	d	d

L360 or X52	0,26	1,40	–	0,030	0,030	d	d	d

L390 or X56	0,26	1,40	–	0,030	0,030	d	d	d

L415 or X60	0,26 e	1,40 e	–	0,030	0,030	f	f	f

L450 or X65	0,26 e	1,45 e	–	0,030	0,030	f	f	f

L485 or X70	0,26 e	1,65 e	–	0,030	0,030	f	f	f

a 0,50 % maximum for copper; 0,50 % maximum for nickel; 0,50 % maximum for chromium; and 0,15 % maximum for molybdenum. For grades up to and including L360/X52, Cu, Cr and Ni shall not be added intentionally. b For each reduction of 0,01 % below the specified maximum concentration for carbon, an increase of 0,05 % above the specified maximum concentration for manganese is permissible, up to a maximum of 1,65 % for grades W L245 or B, but u L360 or X52; up to a maximum of 1,75 % for grades L360 or X52, but L485 or X70; and up to a maximum of 2,00 % for grade L485 or X70. c Unless otherwise agreed, the sum of the niobium and vanadium contents shall be u 0,06 %. d The sum of the niobium, vanadium and titanium concentrations shall be u 0,15 %. e Unless otherwise agreed. f Unless otherwise agreed, the sum of the niobium, vanadium and titanium concentrations shall be u 0,15 %.