Difference between LR EH50 and LR EH55

Jan 27, 2026 Leave a message

LR EH50 and LR EH55 are high-strength structural shipbuilding steel plates, with the primary difference being their minimum yield strength-500 MPa for EH50 and 550 MPa for EH55. Both are Lloyd's Register (LR) certified, Grade E (offering excellent impact toughness at -40° C, and commonly used in heavily loaded, low-temperature marine, or offshore structures.

Application Intensity: EH55 is typically used for higher-stress areas in vessels or offshore rigs compared to EH50.Designation: In LR notation, 'E' signifies the toughness -40° C , 'H' indicates high strength, and the number (50/55) denotes the minimum yield strength in kgf/mm².

Chemical Composition

LR EH50 extra high Strength Chemical Composition
Grade	The Element Max (%)
Grade	C	Si	Mn	P	S	Al	N
LR EH50	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

LR EH55 extra high Strength Chemical Composition
Grade	The Element Max (%)
Grade	C	Si	Mn	P	S	Al	N
LR EH55	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 EH50 extra high strength property
Grade		Mechanical Property			Charpy V Impact Test
Grade	Thickness	Yield	Tensile	Elongation	Degree	Energy 1	Energy 2
LR EH50	mm	Min Mpa	Mpa	Min %	-40	J	J
	t≤50	500	610-770	18%		33	50
	50＜t≤70	500	610-770	18%		33	50
	70＜t≤100	500	610-770	18%		33	50
Note: Energy 1 is transverse impact test, Energy 2 is longitudinal

LR EH55 extra high strength property
Grade		Mechanical Property			Charpy V Impact Test
Grade	Thickness	Yield	Tensile	Elongation	Degree	Energy 1	Energy 2
LR EH55	mm	Min Mpa	Mpa	Min %	-40	J	J
	t≤50	550	670-830	18%		37	55
	50＜t≤70	550	670-830	18%		37	55
	70＜t≤100	550	670-830	18%		37	55
Note: Energy 1 is transverse impact test, Energy 2 is longitudinal