Difference between LR DH62 and LR DH69 steel plate

Dec 19, 2025 Leave a message

The main difference between LR DH62 and LR DH69 is their strength level, with the '69' grade offering higher yield and tensile strength (around 450 MPa yield) compared to the '62' grade (around 355 MPa yield), both being Lloyds Register (LR) certified shipbuilding steels, with 'DH' indicating high tensile strength for colder applications, but '69' signifies superior toughness and strength for more demanding structural uses like decks, hulls, and large components.

Chemical Composition

LR DH62 extra high Strength Chemical Composition
Grade	The Element Max (%)
Grade	C	Si	Mn	P	S	Al	N
LR DH62	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 DH69 extra high Strength Chemical Composition
Grade	The Element Max (%)
Grade	C	Si	Mn	P	S	Al	N
LR DH69	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 DH62 extra high strength property
Grade		Mechanical Property			Charpy V Impact Test
Grade	Thickness	Yield	Tensile	Elongation	Degree	Energy 1	Energy 2
LR DH62	mm	Min Mpa	Mpa	Min %	-20	J	J
	t≤50	620	720-890	17%		41	62
	50＜t≤70	620	720-890	17%		41	62
	70＜t≤100	620	720-890	17%		41	62
Note: Energy 1 is transverse impact test, Energy 2 is longitudinal

LR DH69 extra high strength property
Grade		Mechanical Property			Charpy V Impact Test
Grade	Thickness	Yield	Tensile	Elongation	Degree	Energy 1	Energy 2
LR DH69	mm	Min Mpa	Mpa	Min %	-20	J	J
	t≤50	690	770-940	16%		46	69
	50＜t≤70	690	770-940	16%		46	69
	70＜t≤100	690	770-940	16%		46	69
Note: Energy 1 is transverse impact test, Energy 2 is longitudinal

Key Distinctions:

Strength: 690 grade (DH69) is stronger and tougher than 620 grade (DH62).

Application: DH69 is used for heavier, more critical structures, while DH62 is for general structural parts.

Material Code: 'LR' means Lloyd's Register certified, 'D' means High Tensile, 'H' means Higher Strength, and the number (62/69) indicates minimum yield strength in kg/mm².

In simpler terms: Think of it like different weights of rope; both are strong (DH), but DH69 is like a thicker, heavier rope for bigger loads, while DH62 is for lighter or standard jobs.