Steel Tube for Car Parts / SCM420H SCM440H SCM435 cars steel tubes

Standard:

JIS G3445 Carbon Seamless steel tubes

JIS G4053

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Product Detail

Product Tags

Features

Material Grade:

STKM 11A 12A 12B 12C 13A 13B 13C 14A 14B 14C 15A 15C etc.

Surface Treatment:

1.Bared

2.Black Painted (varnish coating)

3.Galvanized

4.Oiled

5.According to customers.

JIS G3445 Precision steel tubes are mainly used in automobile and precision machinery parts for cars and cylinder. pressure use, and also for transporting steam, water, gas pipe lines.

Chemical composition

Grade		Designation	Unit (%)
			C	Si	Mn	P	S	Nb or V
Grade 11	A	STKM 11A	0.12 max.	0.35 max.	0.60 max.	0.040 max.	0.040 max.	-
Grade 12	A	STKM 12A	0.20 max.	0.35 max.	0.6 max.	0.04 max.	0.04 max.
	B	STKM 12B
	C	STKM 12C
Grade 13	A	STKM 13A	0.25 max.	0.35 max.	0.30~0.90	0.040 max.	0.040 max.	-
	B	STKM 13B
	C	STKM 13C
Grade 14	A	STKM 14A	0.30 max.	0.35 max.	0.30~1.00	0.040 max.	0.040 max.	-
	B	STKM 14B
	C	STKM 14C
Grade 15	A	STKM 15A	0.25~0.35	0.35 max.	0.30~1.00	0.040 max.	0.040 max.	-
	C	STKM 15C
Grade 16	A	STKM 16A	0.35~0.45	0.40 max.	0.40~1.00	0.040 max.	0.040 max.	-
	C	STKM 16C
Grade 17	A	STKM 17A	0.45~0.55	0.40 max.	0.40~1.00	0.040 max.	0.040 max.	-
	C	STKM 17C
Grade 18	A	STKM 18A	0.18 max.	0.55 max.	1.50 max.	0.040 max.	0.040 max.	-
	B	STKM 18B
	C	STKM 18C
Grade 19	A	STKM 19A	0.25 max.	0.55 max.	1.50 max.	0.040 max.	0.040 max.	-
	C	STKM 19C
Grade 20	A	STKM 20A	0.25 max.	0.55 max.	1.60 max.	0.040 max.	0.040 max.	0.15 max

Mechanical properties

Steel Grade		Yield Strength (Mpa)	Tensile Strength (Mpa)	Elongation（%）
Name	No.	ReH (min)	Rm(min)	A(min)
STKM 11A		_	290	35
STKM 12A		175	340	35
STKM 12B		275	390	25
STKM 12C		355	4700	20
STKM13A		215	370	30
STKM 11B		305	440	20
STKM11C		380	510	15

Tolerance

SIZE	Allowable tolerance		Special Tolerance
SIZE	OD	WT	OD	WT
4mm-20mm	±0.25mm	<3mm±0.3mm; ≥3mm ±10%	±0.05mm	±0.05mm
20mm-30mm	±0.25mm		±0.08mm	±0.08mm
31mm-40mm	±0.25mm		±0.10mm	±0.08mm
41mm-49mm	±0.25mm		±0.15mm	±0.15mm
50mm-80mm	±0.5%		±0.20mm	±0.20mm
81mm-120mm	±0.5%		±0.30mm	±0.30mm

Delivery condition

Designation	Symbol	Description
Cold finished (hard)	BK(+C)	Tubes do not undergo heat treatment following the final cold forming and, thus, have a rather high resistance to deformation
Cold finished (Soft)	BKW	The final heat treatment is followed by cold drawing involving limited deformation. Appropriate further processing allows a certain degree of cold forming (e.g. bending, expanding)
Cold finished (Soft)	(+LC)
Cold finished and stress-relieved	BKS(+SR)	Heat treatment is applied following the last cold forming process. Subject to appropriate processing conditions, the increase in the residual stresses involved enables both forming and machining to a certain degree.
Annealed	GBK(+A)	The last Cold forming process is followed by annealing in a controlled atmosphere.
Normalized	NBK(+N)	The last cold forming process is followed by annealing above the upper transformation point in a controlled atmosphere.

Delivery condition

Designation	Symbol	Description
Cold finished (hard)	BK(+C)	Tubes do not undergo heat treatment following the final cold forming and, thus, have a rather high resistance to deformation
Cold finished (Soft)	BKW	The final heat treatment is followed by cold drawing involving limited deformation. Appropriate further processing allows a certain degree of cold forming (e.g. bending, expanding)
Cold finished (Soft)	(+LC)
Cold finished and stress-relieved	BKS(+SR)	Heat treatment is applied following the last cold forming process. Subject to appropriate processing conditions, the increase in the residual stresses involved enables both forming and machining to a certain degree.
Annealed	GBK(+A)	The last Cold forming process is followed by annealing in a controlled atmosphere.
Normalized	NBK(+N)	The last cold forming process is followed by annealing above the upper transformation point in a controlled atmosphere.

High Precision Steel Tubes in Stock
OD	Thickness(mm)
mm	Thickness(mm)
4	4*1
6	6*1	6*1.5	6*2
8	8*1	8*1.5	8*2
10	10*1	10*1.5	10*2	10*2.5
12	12*1	12*1.5	12*2	12*2.5	12*3
14	14*1	14*1.5	14*2	14*2.5	14*3
15	15*1	15*1.5	15*2	15*2.5	15*3	15*3.5
16	16*1	16*1.5	16*2	16*2.5	16*3	16*3.5	16*4	16*4.5
18	18*1	18*1.5	18*2	18*2.5	18*3	18*3.5	18*4	18*4.5
20	20*1	20*1.5	20*2	20*2.5	20*3	20*3.5	20*4	20*4.5	20*5
22	22*1	22*1.5	22*2	22*2.5	22*3	22*3.5	22*4	22*4.5	22*5
25	25*1	25*1.5	25*2	25*2.5	25*3	25*3.5	25*4	25*4.5	25*5
28	28*1	28*1.5	28*2	28*2.5	28*3	28*3.5	28*4	28*4.5	28*5
30	30*1	30*1.5	30*2	30*2.5	30*3	30*3.5	30*4	30*4.5	30*5	30*6
32		32*1.5	32*2	32*2.5	32*3	32*3.5	32*4	32*4.5	32*5	32*6
34		34*1.5	34*2	34*2.5	34*3	34*3.5	34*4	34*4.5	34*5	34*6
35		35*1.5	35*2	35*2.5	35*3	35*3.5	35*4	35*4.5	35*5	35*6
38			38*2	38*2.5	38*3	38*3.5	38*4	38*4.5	38*5	38*6
40			40*2	40*2.5	40*3	40*3.5	40*4	40*4.5	40*5	40*6
42			42*2	42*2.5	42*3	42*3.5	42*4	42*4.5	42*5	42*6
45			45*2	45*2.5	45*3	45*3.5	45*4	45*4.5	45*5	45*6
46			46*2	46*2.5	46*3	46*3.5	46*4	46*4.5	46*5	46*6
48			48*2	48*2.5	48*3	48*3.5	48*4	48*4.5	48*5	48*6
50			50*2	50*2.5	50*3	50*3.5	50*4	50*4.5	50*5	50*6
54				54*2.5	54*3	54*3.5	54*4	54*4.5	54*5	54*6
60				60*2.5	60*3	60*3.5	60*4	60*4.5	60*5	60*6
65					65*3	65*3.5	65*4	65*4.5	65*5	65*6
75						75*3.5	75*4	75*4.5	75*5	75*6
76							76*4	76*4.5	76*5	76*6
89										89*6
Note： We could produce other sizes as your requirements. Surface Treatment: Bright, Galvanized, Phosphate etc.

Manufacture Process

Advantages

Strengthen the inspection of products in each production stage, equipped with complete testing equipment: non-destructive eddy current testing, high pressure resistance testing machine, universal mechanical tensile testing machine, bending flattening flares testing machine, cleanliness analyzer, metal element analyzer, etc. Meet the mechanical properties of products, process performance test, provide a powerful guarantee for qualified products .