Difference between S500QL and S5000QL steel plate

Jan 08, 2026 Leave a message

S500QL and S620QL are both high-strength, quenched & tempered (Q+T) structural steels under EN 10025-6, with the main difference being their yield strength and impact toughness: S500QL has a minimum yield strength of 500 MPa and lower temperature toughness (e.g., -40°C), while S620QL has a higher minimum yield strength of 620 MPa but typically tested at warmer temperatures (e.g., -20°C for S620Q, or potentially colder for S620QL1).

Chemical Composition

S500QL1Chemical Composition
Grade	The Element Max (%)
Grade	C	Si	Mn	P	S	N	B	Cr
S500 QL1	0.20	0.80	1.70	0.020-0.025	0.010-0.015	0.015	0.005	1.50
	Cu	Mo	Nb	Ni	Ti	V	Zr
	0.50	0.70	0.06	2.0	0.05	0.12	0.15

S620QLChemical Composition
Grade	The Element Max (%)
Grade	C	Si	Mn	P	S	N	B	Cr
S620 QL	0.20	0.80	1.70	0.020-0.025	0.010-0.015	0.015	0.005	1.50
	Cu	Mo	Nb	Ni	Ti	V	Zr
	0.50	0.70	0.06	2.0	0.05	0.12	0.15

Mechanical Property

Grade	S620QL Mechanical Property
Grade	Thickness	Yield	Tensile	Elongation	Min Impact Energy
S620 QL	mm	Min Mpa	Mpa	Min %	-40	30J
	3<t≦50	620	700-890	15	-40	30J
	50<t≦100	580	700-890	15	-40	30J
	100<t≦150	560	650-830	15	-40	30J

Grade	S500QL1Mechanical Property
Grade	Thickness	Yield	Tensile	Elongation	Min Impact Energy
S500 QL1	mm	Min Mpa	Mpa	Min %	-60	30J
	3<t≦50	500	590-770	17	-60	30J
	50<t≦100	480	590-770	17	-60	30J
	100<t≦150	440	540-720	17	-60	30J

Key Differences

"S": Signifies "Structural Steel".

"500" vs. "620": The number indicates the minimum yield strength in megapascals (MPa).

S500QL: Minimum yield strength of 500 MPa.

S620QL: Minimum yield strength of 620 MPa, making it stronger.

"Q": Means "Quenched" (delivery condition).

"L": Denotes "Tempered" (delivery condition) and specifies a low-temperature impact test (often -40°C for S500QL).