55Si 7 1.0904 - DIN 17222-1979

Grade	55Si 7
Germany W-Nr.	1.0904
Corresponding Standard	DIN 17222-1979 Cold Rolled Steel Strips for Springs Technical Condition of Delivery
Classification	Spring Steel

55Si 7 Chemical Element Composition Content (%)

Component	C	Si	Mn	P	S
Minimum Value	0.52	1.5	0.7	-	-
Maximum Value	0.6	1.8	1	0.045	0.045

55Si 7 Mechanical Properties

thickness t mm	Mark	Heat Treatment or Condition	Tensile Strength σ_b Mpa	Elongation or Extension Rate δ %	Hardness HBW
t≤3*	55Si 7 G	Cold Rolled + Soft Annealing (G)	≤740	≥10	HV** ≤220
t≤2****	55Si 7 H+A	Cold Rolled + Quenching + Tempering (H+A)	*** 1300~1800		385~535
t≤2		Quenching			≥650

Approximate Comparison Table Spring Steel

55Si7 Corresponding Standards(Same grade name, different standards)

Note: The data is for reference only! If you have any questions, please fill out "I want to correct it"!