QUALITY ASSURANCE

GB8163


The chemical composition, mechanical properties:

standard



Grade



chemical composition (%)









C

Mn

Si

Cr

Ni

Cu

P.S

GB/T8163



10

0.07~0.13

0.35~0.65

0.17~0.37

≤0.15

≤ 0.30

≤ 0.25

≤ 0.030

20

0.17~0.23

0.35~0.65

0.17~0.37

≤0.25

≤ 0.25

≤ 0.25

≤ 0.030

Q345

0.12~0.20

1.20~1.60

0.20~0.55

≤ 0.030

Mechanical Properties




Tensile Strength (MPa)

Yield Strength (MPa)

Elongation (%)

10

335~475

≥ 205

≥ 24

20

410~550

≥ 245

≥ 20

Q345

490~665

≥ 325

≥ 21


Dimensions and Tolerances:

Steel pipe type


Pipe sizes

Tolerance

mm

Normal

expert

Hot rolled (extrusion, expanding tube



Outside Diameter

All

+1%(min+0.50)

-

Wall Thickness


All


+15%(min +0.45)

-


-12.5%(min -0.40)

Cold drawing (rolling) tube









Outside Diameter




6~10

+0.20

+0.15

>10~30

+0.40

+0.20

>30~50

+0.45

+0.30

>50

+1%

+0.8%

Wall Thickness





≤1

+0.15

+0.12

>1~3


+15%

+12.5%

-10%

-10%

>3


+12.5%

+10%


-10%

* note: not less than 351 mm in diameter thermal expanding, wall thickness tolerance of +18