Good roughness for cylinder using cold rolled seamless honed tube

Standard

DIN2391, DIN2445, EN10305, GB/T 3639, GB 8713

Grade

ST35(E235), ST37, ST24(E255), ST52(E355), 10#, 20#, 35#, 45#

O.D.

4.0MM-400MM

W.T.

0.5MM-18MM

Surface Treatment

bare, varnished, oiled, anti-corrosion coating as request

Packing

1. bundle packing

2. marking as per customer's requests

3. paint on the pipe as per customer request

4. pipe caps as customer request

Condition of Delivery

1. NBK(+N)

after cold forming, eventually above phase transition point, in a protective atmosphere of annealing oxidation medium

2. GBK(+A)

after cold forming, annealing in non oxidizing medium protective gas

3. BK(+C)

the final heat treatment after cold forming, therefore small steel pipe plastically, the plastically degree does not guarantee

4. BKW(+LC)

after final heat treatment, a tiny cold drawing deformation, continue again when machining steel pipe allowed inside certain limits cold deformation(bending, flaring)

5. BKS(+SR)

have a stress relief after cold forming, heat treatment, steel pipe can be carried out within a certain limit in the appropriate processing again

Processing

Cylinder Diameter

Straightness

Size Accuracy

W.T/mm

Inner Bore Roughess

Cold drawn/

cold rolled

ID30-250

0.3

H9-H11

±10%

0.4~1.6um

Honed tube

ID50-250

0.3

H7-H9

±10%

<0.4um

Material

Tensile strength

Yield strength

Elongation

Hardness

Ck20/20#/AISI1020

>520 N/ mm²

>375 N/mm2

>15%

>85HB

Ck45/45#/AISI1045

>600 N/ mm²

>520 N/ mm²

>15%

>85HB

ST52/16Mn/Q345D

>600 N/ mm²

>520 N/ mm²

>15%

>85HB

25Mn/STKM 13C-T

>600 N/ mm²

>530 N/ mm²

>15%

>85HB

ID size

ID deviation (mm)

H7

H8

H9

H10

30

+0.021

0

+0.033

0

+0.052

0

+0.084

0

>30~50

+0.025

0

+0.039

0

+0.062

0

+0.100

0

>50~80

+0.030

0

+0.046

0

+0.074

0

+0.120

0

>80~120

+0.035

0

+0.054

0

+0.087

0

+0.140

0

>120~180

+0.040

0

+0.063

0

+0.100

0

+0.160

0

>180~250

+0.046

0

+0.072

0

+0.115

0

+0.185

0

>250~315

+0.052

0

+0.081

0

+0.130

0

+0.210

0

>315~400

+0.0527

0

+0.089

0

+0.140

0

+0.230

OD x WT

OD x WT

OD x WT

OD x WT

48*31.75

98*80

154*130

45*35

45*30

100*85

137*115

35*25

25*19

121*100

94*80

125*100

50*40

120*100

90*80

90*70

40*30

140*120

80*70

100*70

65*50

123*105

111*95

120*100

70*57

146*125

50.5*44.5

31*25

48*40

165*140

158*135

76*55

58*50

176*150

160*135

77*57

60*50

194*160

149*125

77*59

70*50

30*25

42.5*31

Other size can work

95*80

128*110

190*160

Condition

Material Grade

T.S (Mpa)

Y.S (MPa)

Elongation (%)

BKS

ST35 (10#)

≥420

≥315

≥14

BKS

ST45(20#)

≥520

≥375

≥12

BKS

ST52(16Mn)

≥580

≥420

≥10

GBK

ST35 (10#)

≥315

≥35

GBK

ST45(20#)

≥390

≥32

GBK

ST52(16Mn)

≥490

≥30

NBK

ST35 (10#)

340-470

≥235

≥32

NBK

ST45(20#)

440-570

≥255

≥30

NBK

ST52(16Mn)

490-630

≥335

≥28