Standard

  Grade

Chemical  Composition%

C

Mn

P

S

Si

Cr

Ni

Cu

GOST 9567-75

10

0.07-0.14

0.35-0.65

≤0.025

≤0.03

0.17-0.37

≤0.15

≤0.30

≤0.30

10G2

0.07-0.15

1.20-1.60

≤0.035

≤0.035

0.17-0.37

≤0.30

≤0.30

≤0.30

20

0.17-0.24

0.35-0.65

≤0.025

≤0.03

0.17-0.37

≤0.25

≤0.25

≤0.30

35

0.32-0.40

0.50-0.80

≤0.035

≤0.040

0.17-0.37

≤0.25

≤0.30

≤0.30

45

0.42-0.45

0.50-0.80

≤0.035

≤0.040

0.17-0.37

≤0.25

≤0.30

≤0.30

15ChM

0.11-0.18

0.40-0.70

≤0.025

≤0.025

0.17-0.37

0.80-1.10

≤0.30

≤0.30

20Ch

0.17-0.23

0.50-0.80

≤0.035

≤0.035

0.17-0.37

0.70-1.00

≤0.30

≤0.30

Standard

  Grade

Mechanical Properties

Tensile Strength(Mpa)

Yield Strength(Mpa)

Elongation(%)

GOST 9567-75

Hot rolled

10

≥353

≥216

≥24

10G2

≥421

≥265

≥21

20

≥412

≥245

≥21

35

≥510

≥294

≥17

45

≥588

≥323

≥14

15ChM

≥431

≥225

≥21

20Ch

≥431

-

≥16

Standard

  Grade

Mechanical Properties

Tensile Strength(Mpa)

Yield Strength(Mpa)

Elongation(%)

GOST 9567-75

Cold drawn

10

≥343

≥206

≥24

10G2

≥422

≥245

≥22

20

≥412

≥245

≥21

35

≥510

≥294

≥17

45

≥589

≥323

≥14

15ChM

≥431

≥226

≥21

20Ch

≥431

-

≥17

Designation

Symbol

Description

Cold finished (hard)

BK

Tubes do not undergo heat treatment following the final cold forming and, thus, have a rather high resistance to deformation.

Cold finished (soft)

BKW

The final heat treatment is followed by cold drawing involving limited deformation. Appropriate further processing allows a certain degree of cold forming (e.g. bending, expanding).

Cold finished and stress-relieved

BKS

Heat treatment is applied following the last cold forming process. Subject to appropriate processing conditions, the increase in the residual stresses involved enables both forming and machining to a certain degree.

Annealed

GBK

The last cold forming process is followed by annealing in a controlled atmosphere.

Normalized

NBK

The last cold forming process is followed by annealing above the upper transformation point in a controlled atmosphere.