Difference between LR EH40 and LR EH42

Jan 27, 2026 Leave a message

LR EH40 and LR EH42 are high-strength, low-alloy (HSLA) shipbuilding steel plates certified by Lloyd's Register (LR), designed for low-temperature service denotes extreme low temperature, -40° C. They are primarily used in critical, high-stress hull structures, with EH42 offering a higher yield strength (420 MPa) than EH40 (400 MPa).

Chemical Composition

LR EH40 high Strength Chemical Composition
Grade	The Element Max (%)
Grade	C	Si	Mn	P	S	Al	N
LR EH40	0.18	0.05	0.9-1.6	0.035	0.035	0.015
	Nb	V	Ti	Cu	Cr	Ni	Mo
	0.02-0.05	0.03-0.10	0.02	0.35	0.20	0.40	0.08

LR EH42 extra high Strength Chemical Composition
Grade	The Element Max (%)
Grade	C	Si	Mn	P	S	Al	N
LR EH42	0.20	0.55	1.70	0.030	0.030	0.015	0.020
	Nb	V	Ti	Cu	Cr	Ni	Mo
	0.02-0.05	0.03-0.10	0.02

Mechanical Property

LR EH40 high strength property
Grade		Mechanical Property			Charpy V Impact Test
Grade	Thickness	Yield	Tensile	Elongation	Degree	Energy 1	Energy 2
LR EH40	mm	Min Mpa	Mpa	Min %	-40	J	J
	t≤50	390	510-650	20%		26	39
	50＜t≤70	390	510-650	20%		31	46
	70＜t≤100	390	510-650	20%		37	55
Note: Energy 1 is transverse impact test, Energy 2 is longitudinal

LR EH42 extra high strength property
Grade		Mechanical Property			Charpy V Impact Test
Grade	Thickness	Yield	Tensile	Elongation	Degree	Energy 1	Energy 2
LR EH42	mm	Min Mpa	Mpa	Min %	-40	J	J
	t≤50	420	530-680	20%		28	42
	50＜t≤70	420	530-680	20%		28	42
	70＜t≤100	420	530-680	20%		28	42
Note: Energy 1 is transverse impact test, Energy 2 is longitudinal

Key Details on LR EH40 and LR EH42

LR EH40: A high-strength, low-alloy steel designed for ships operating in cold climates, with a minimum yield strength of 400 MPa and excellent notch toughness down to -40° C.

LR EH42: An even higher strength grade (420 MPa yield strength) suitable for even more demanding structural applications in shipbuilding.

Application: Both grades are used in the construction of ship hulls, offshore platforms, and marine structures, especially for vessels navigating in freezing temperatures.

Certification: Certified by Lloyd's Register, ensuring they meet specific requirements for shipbuilding materials.