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Standard

GB/T8163 Chinese national standard

Diamensional tolerances:

Types of steel tubes

Outer diameter

Wall thickness

Cold-rolled tubes

Tube sizes(mm)

Tolerances(mm)

Tube sizes (mm)

Tolerances(mm)

3050

±0.3

≤30

±10

50219

±0.8

Mechanical properties:

Standard codes

Models of steel tubes

Tensite strengthMPa

Yield strengthMPa

Elongation

GB/T8163

10

335475

≥205

≥24

20

410550

≥245

≥20

Q345

490665

≥325

≥21

Chemical composition:

Standard codes

Models of steel tubes

Chemical compositions

C

Si

Mn

P

S

Cr

Ni

Cu

GB/T8163

10

0.070.14

0.170.37

0.350.65

≤0.035

≤0.035

≤0.15

≤0.25

≤0.25

20

0.170.24

0.170.37

0.350.65

≤0.035

≤0.035

≤0.25

≤0.25

≤0.25

Q345

0.120.20

0.200.55

1.201.60

≤0.045

≤0.045

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