JIS G3445 STKM 11A, STKM12ABC,STKM13ABC,STKM 14ABC
Carbon steel tubes for machine structural purposes
Application
Machinery, Automobiles, Bicycles,Furniture, Appliances and Other machine parts.
Size Range
O.D 12.7-110mm
W.T 1.2-14mm
Length: 3-12M or according to your requirements
|
Standard |
Grade |
Chemical Composition% |
||||
|
C |
Mn |
P |
S |
Si |
||
|
JIS G3445 |
STKM 11A |
≤0.12 |
≤0.60 |
≤0.04 |
≤0.04 |
≤0.35 |
|
STKM 12A |
≤0.20 |
≤0.60 |
≤0.04 |
≤0.04 |
≤0.35 |
|
|
STKM 12B |
≤0.20 |
≤0.60 |
≤0.04 |
≤0.04 |
≤0.35 |
|
|
STKM 12C |
≤0.20 |
≤0.60 |
≤0.04 |
≤0.04 |
≤0.35 |
|
|
STKM 13A |
≤0.25 |
0.3~0.9 |
≤0.04 |
≤0.04 |
≤0.35 |
|
|
STKM 13B |
≤0.25 |
0.3~0.9 |
≤0.04 |
≤0.04 |
≤0.35 |
|
|
STKM 13C |
≤0.25 |
0.3~0.9 |
≤0.04 |
≤0.04 |
≤0.35 |
|
|
Standard |
Grade |
Mechanical Properties |
||
|
Tensile Strength(Mpa) |
Yield Strength(Mpa) |
Elongation(%) |
||
|
JIS G3445 |
STKM 11A |
≥290 |
- |
≥35 |
|
STKM 12A |
≥340 |
≥175 |
≥35 |
|
|
STKM 12B |
≥390 |
≥275 |
≥25 |
|
|
STKM 12C |
≥470 |
≥355 |
≥20 |
|
|
STKM 13A |
≥370 |
≥215 |
≥30 |
|
|
STKM 13B |
≥440 |
≥305 |
≥20 |
|
|
STKM 13C |
≥510 |
≥380 |
≥15 |
|
|
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. |
Chemical Composition,Mechanical Properties,Visual appearance and dimensions Test,NDT,Grain Size Test.
Oil-dip,varnish,Shot Blasting
