Large Diameter St37.4 Cold Drawn Carbon Seamless Steel Tube

Production

Large Diameter St37.4  Cold Drawn Carbon Seamless Steel Tube

Standard

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

Inner  Diameter

30mm~250mm

Wall Thickness

0.5mm~18mm

Material

10#~45#,16Mn,Q195~Q345,ST35~ST52

 Length

as customers required

Surface treatment

As customers required

 Package

 1. bundle packing

2. marking as per customer's requests

3. paint on the pipe as per customer request

4. pipe caps as customer reques

Min Order Quantity

According to customer's requirement

Payment terms

L/C, T/T

Contact

If you have any questions, please feel free to contact me.

Delivery conditions

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 plastic, the plastic 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

OD

GB/T3639(GB8713)

DIN2391(EN10305)

Our Tolerence

Best Quality

4-30mm

±0.10mm

±0.08mm

±0.05mm

±0.02mm

31-40mm

±0.15mm

±0.15mm

±0.05mm

±0.03mm

41-50mm

±0.20mm

±0.20mm

±0.05mm

±0.03mm

51-60mm

±0.25mm

±0.25mm

±0.08mm

±0.03mm

61-70mm

±0.30mm

±0.30mm

±0.10mm

±0.05mm

71-160mm

±0.30mm

±0.30mm

±0.10mm

±0.05mm

Tolerance in WT

±0.12mm

±0.10mm

±0.05mm

±0.03mm

Process

Diameter

Length

Precision

Inner Hole Roughness

Cold Rolled

30-100mm

≤12 m

H8-H10

0.4-1.6

Cold Draw

30-250mm

≤12 m

H8-H10

0.8-1.6

Honing

40-500mm

≤12 m

H8-H9

0.4-0.8

Rolling

40-400mm

≤7 m

H8

0.4

Inner Diameter

H8

H9

H10

30mm

±0.033

±0.052

±0.084

5-30mm

30-50mm

±0.039

±0.062

±0.100

±0.080

50-80mm

±0.046

±0.074

±0.120

80-120mm

±0.054

±0.087

±0.140

120-180mm

±0.063

±0.100

±0.160

180-250mm

±0.072

±0.115

±0.185

250-315mm

±0.081

±0.130

±0.210

315-400mm

±0.089

±0.140

±0.230

1.100% PMI,Spectro Chemical Aanlysis Test for Raw Material

2.100% Dimension & Visual Examination 

3. Mechanical Properties Test Include Tension Test,Flaring Test (For Seamless tube/pipe)/ Flange Test (For Welded Pipe & Tube), Hardness Test ,Reversed Flattening Test

4.100% Hydrostatic Test or 100% NON-DESTRUCTIVE Test  (ET or UT) 

5.Radiographic Test for Welded Pipe (shall be accordance with specification,or shall be as agreed upon between the purchaser and vendor)

6.Straightness Test  (optional)

7.Roughness Test (optional)

8.Intergranular Corrosion Test(optional)