STKM 11A STKM 12A STKM 13A Steel Tubes

STKM11A STKM 12A STKM 13A STEEL TUBES

JIS G3445 STKM11A, STKM 12A, STKM 12C, STKM13A is the standard applicable to carbon steel tubes for machine structural purposes

Application

JIS G3445 STKM 11A, STKM 12A, STKM 12C, STKM 13A, STKM 13C, STKM 15A, STKM 15C, STKM 17A, STKM 17C carbon steel tubes used for machinery, automobiles, bicycles, furniture, appliances and other machine parts.

Grade and Designation
The grade and designation of the tube shall be as given as follows table
The sub classification letter symbols A, B and C are used to indicate distinction of method of manufacturing the tube, cold working process, heat treatment, etc.

Grade		Designation
Grade 11	A	STKM 11A
Grade 12	A	STKM 12A
	B	STKM 12B
	C	STKM 12C
Grade 13	A	STKM 13A
	B	STKM 13B
	C	STKM 13C
Grade 14	A	STKM 14A
	B	STKM 14B
	C	STKM 14C
Grade 15	A	STKM 15A
Grade 15	C	STKM 15C
Grade 16	A	STKM 16A
Grade 16	C	STKM 16C
Grade 17	A	STKM 17A
Grade 17	C	STKM 17C
Grade 18	A	STKM 18A
	B	STKM 18B
	C	STKM 18C
Grade 19	A	STKM 19A
Grade 19	C	STKM 19C
Grade 20	A	STKM 20A

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.	0.60 max.	0.040 max.	0.040 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.

Click to download the details of STKM 11A STKM 12A STKM 13A Steel Tubes.

Mechanical Properties

Designation	Tensile strength N/П {kgf/П}	Yield point or proof N/П {kgf/П}	Elongation %		Flattening strength Distance between flat plates (H) (D is outside dia. of the tube)	Bending strength
			No. 4	No. 4		Bend angle	Inside radius
			No. 11	No. 5			Inside radius
			No. 12				(D is outside dia. of the tube)
			test pieces Longitudinal direction	test pieces Transverse direction			(D is outside dia. of the tube)
STKM11A	290{30} min.	–	35 min.	30 min.	1/2 D	180	4 D
STKM12A	340{35} min.	175{18} min.	35 min.	30 min.	2/3 D	90	6 D
STKM12B	390{40} min.	275{28} min.	25 min.	20 min.	2/3 D	90	6 D
STKM12C	470{48} min.	355{36} min.	20 min.	15 min.	–	–	–
STKM13A	370{38} min..	215{22} min.	30 min.	25 min.	2/3 D	90	6 D
STKM13B	440{45} min..	305{31} min.	20 min.	15 min.	3/4 D	90	6 D
STKM13C	510{52} min..	380{39} min.	15 min.	10 min.	–	–	–
STKM14A	410{42} min..	245{25} min.	25 min.	20 min.	3/4 D	90	6 D
STKM14B	500{51} min.	355{36} min.	15 min.	10 min.	7/8 D	90	8 D
STKM14C	550{56} min..	410{42} min.	15 min.	10 min.	–	–	–
STKM15A	470{48} min..	275{28} min.	22 min.	17 min.	3/4 D	90	6 D
STKM15C	580{59} min..	430{44} min.	12 min.	7 min.	–	–	–
STKM16A	510{52} min..	325{33} min.	20 min.	15 min.	7/8 D	90	8 D
STKM16C	620{63} min..	460{47} min.	12 min.	7 min.	–	–	–
STKM17A	550{56} min..	345{35} min.	20 min.	15 min.	7/8 D	90	8 D
STKM17C	650{66} min..	480{49} min.	10 min.	5 min.	–	–	–
STKM18A	440{45} min..	275{28} min.	25 min.	20 min.	7/8 D	90	6 D
STKM18B	490{50} min..	315{32}min.	23 min.	18 min.	7/8 D	90	8 D
STKM18C	510{52} min.	380{39} min.	15 min.	10 min.	–	–	–
STKM19A	490{50} min.	315{32} min.	23 min.	18 min.	7/8 D	90	6 D
STKM19C	550{56} min.	410{42} min.	15 min.	10 min.	–	–	–
STKM20A	540{55} min.	390{40} min.	23 min.	18 min.	7/8 D	90	6 D

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Appearance

The tubes shall be practically straight. and the two ends shall be at right angles to the axis of the tube
The tubes shall be free from defects detrimental to practical use.
The surface finish of the tubes, when especially specified shall be agreed upon by the purchaser and the manufacturer.

Tolerance on Outside Diameter

Division	Tolerances on outside diameter
No. 1	Under 50mm ±0.5mm
No. 1	50mm or over ±1%
No. 2	Under 50mm ±0.25mm
No. 2	50mm or over ±0.5%
No. 3	Under 25mm ±0.12mm
	25mm or over to and excl. 40mm ±0.15mm
	40mm or over to and excl. 50mm ±0.18mm
	50mm or over to and excl. 60mm ±0.20mm
	60mm or over to and excl. 70mm ±0.23mm
	70mm or over to and excl. 80mm ±0.25mm
	80mm or over to and excl. 90mm ±0.30mm
	90mm or over to and excl.100mm ±0.40mm
	100mm or over ±0.50%

Tolerance on Thickness

Division	Tolerances on wall thickness
No. 1	Under 4mm
	+0.6mm
	-0.5mm
	4mm or over
	15%
	-12.50%
N. 2	Under 3mm
	±0.3mm
	3mm or over

Standard: JIS G3445

Description Name: STKM 11A Steel tube, STKM 12A steel tubes, STKM 12C steel tubes, STKM 13A steel tubes, STKM 13C steel tubes

Size: 4mm-89mm

W.T.: 1mm-15mm

Shape: Round

Production type: Cold drawn, cold rolled or hot rolled. welding

Length: Single random length/ Double random length or as customer’s actual request max length is 10m

Grade: STKM 11A, STKM 12A, STKM 12C, STKM 12B, STKM 13A, STKM 13B, STKM 13C, STKM 15A, STKM 17A,

Marking

Each tube having passed the inspection shall be legibly marked with the following items, the order of arranging the items is not specified.
However, for smaller tubes or on a request from the purchaser, tubes may be bundled together and marked for each bundle by suitable means.
(1) Designation of grade
(2) Letter symbol indicating the manufacturing process

Note:

Mill test certificates will be issued according to EN10204.3
The tubes Shall be Seamless or Welded.

Protection and Packing:

Packed in wooden box or bundles protected with plastic paper, and suitably protected for sea-worthily delivery or as requested.
The tubes shall be delivered with a temporary corrosion protection. The type of protection shall be at the discretion of the manufacturer