GOST 8639-82. Square Steel Pipes
Side (A): 10 - 120 mm
Wall Thickness (WT): 1 - 9 mm
Tolerances:
On the side:
A 10 - 30 mm: ± 0,3 mm,
A 35 - 50 mm: ± 0,4 mm,
A 60 - 120 mm: ± 0,8 %
On the WT:
electro-welded pipes: ± 10%,
Cold-formed pipes: ± 12,5 %
Notes:
Cold-formed stainless steel pipes are produced from steel grades: 10, 20, 35, 45. Electric-welded pipes are produced from steel grades: 08kp, 10, 10ps, 20, St2sp, St2kp, St2ps, St4sp, St4ps, St4kp.
Random length - 1,5 - 9 m, fixed length - 5 - 9 m.
Technical requirement according to GOST 13663-86.
Seamless cold-formed steel tube are produced heat-treated. Straightening and cropping of ends of pipes are subject to agreement. Electric-welded pipes are produced without heat treatment, with raw end face.
Non-destructive test of quality of welded seam is carried out before profiling of electric-welded pipes.
| Sizes |
Side A, mm |
Wall Thickness, mm |
1 |
1,5 |
2 |
2,5 |
3 |
3,5 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
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15 |
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20 |
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25 |
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30 |
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35 |
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40 |
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42 |
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45 |
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50 |
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60 |
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70 |
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80 |
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90 |
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100 |
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110 |
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120 |
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| Colors in table: |
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Electro-welded pipes |
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Electro-welded and cold-formed |
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Cold-formed |
| Mechanical Properties |
Steel Grade |
|
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Elongation, % (min) |
10 |
343 |
206 |
24 |
20 |
412 |
245 |
20 |
35 |
510 |
294 |
18 |
45 |
549 |
323 |
14 |
| Chemical Composition (%, max) |
Steel Grade |
C |
Si |
Mn |
Cr |
Ni/div> |
Mo |
S |
P |
Cu |
N |
08kp |
0,05-0,12 |
0,03 |
0,25-0,50 |
0,10 |
- |
0,04 |
0,035 |
- |
- |
0,006 |
10 |
0,07-0,14 |
0,17-0,37 |
0,35-0,65 |
0,15 |
0,3 |
- |
- |
- |
- |
- |
10ps |
0,07-0,14 |
0,05-0,17 |
0,35-0,65 |
0,15 |
0,3 |
- |
0,04 |
0,035 |
0,3 |
- |
10kp |
0,07-0,14 |
0,07 |
0,35-0,65 |
0,15 |
0,3 |
- |
0,04 |
0,035 |
0,3 |
- |
20 |
0,17-0,24 |
0,17-0,37 |
0,35-0,65 |
0,25 |
0,25 |
- |
0,03 |
0,025 |
0,3 |
- |
35 |
0,32-0,40 |
0,17-0,37 |
0,50-0,80 |
0,25 |
0,30 |
- |
0,04 |
0,035 |
0,3 |
- |
45 |
0,42-0,45 |
0,17-0,37 |
0,50-0,80 |
0,25 |
- |
- |
0,04 |
0,035 |
- |
- |
St2sp |
0,09-0,15 |
0,15-0,30 |
0,25-0,50 |
0,30 |
- |
- |
0,05 |
0,04 |
- |
0,01 |
St2ps |
0,09-0,15 |
0,05-0,15 |
0,25-0,50 |
0,30 |
- |
- |
0,05 |
0,04 |
- |
0,01 |
St4sp |
0,18-0,27 |
0,15-0,30 |
0,40-0,70 |
0,30 |
- |
- |
0,05 |
0,04 |
- |
- |
St4ps |
0,18-0,27 |
0,05-0,15 |
0,40-0,70 |
0,30 |
- |
- |
0,05 |
0,04 |
- |
- |
St4kp |
0,18-0,27 |
0,05 |
0,40-0,70 |
0,30 |
- |
- |
0,05 |
0,04 |
- |
- |
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