Standard:JIS3445
Usages:Suitable for carbon steel pipe used in machinery, automobile, bicycle, apparatus and other mechanical parts.
Steel Grades:STKM11A、STKM12(A,B,C)、STKM13(A,B,C)、STKM14(A,B,C)

Chemical composition of different steel grades:

Standard	Steel Grades	Chemical composition(%)
		C	Si	Mn	P	S
JIS G3445	STKM11A	≤0.12	≤0.35	≤0.60	≤0.040	≤0.040
	STKM12A	≤0.20	≤0.35	≤0.60	≤0.040	≤0.040
	STKM12B
	STKM12C
	STKM13A	≤0.25	≤0.35	0.30-0.90	≤0.040	≤0.040
	STKM13B
	STKM13C
	STKM14A	≤0.30	≤0.35	0.30-1.00	≤0.040	≤0.040
	STKM14B
	STKM14C

Mechanical properties of different steel grades:

Standard	Steel grades	Mechanical properties
		Tensile strength(Mpa)	Yield strength(Mpa)	Elongation(%)
JIS G3445	STKM11A	≥295	/	≥35
	STKM12A	≥345	≥175	≥35
	STKM12B	≥390	≥275	≥25
	STKM12C	≥470	≥355	≥20
	STKM13A	≥375	≥215	≥30
	STKM13B	≥440	≥345	≥20
	STKM13C	≥510	≥380	≥15
	STKM14A	≥410	≥245	≥25
	STKM14B	≥500	≥355	≥15
	STKM14C	≥550	≥410	≥15