JIS Standards
Mechanical Tube
Standard
JIS G3445
Application
It is used for machinery, automobile, bicycle, furniture and components for other machines.
Main Steel Tube Grades
STKM11A, STKM12(A,B,C), STKM13(A,B,C), STKM14(A,B,C)
Chemical Composition
| Standard | Steel Grade | Chemical Composition % | ||||
| C | Si | Mn | P | S | ||
| JIS G3445 | STKM11A | ≤0.12 | ≤0.35 | ≤0.60 | ≤0.040 | ≤0.040 |
| STKM12A | ≤0.20 | ≤0.35 | ≤0.60 | ≤0.040 | ≤0.040 | |
| STKM12B | ||||||
| STKM12C | ||||||
| STKM13A | ≤0.25 | ≤0.35 | 0.30-0.90 | ≤0.040 | ≤0.040 | |
| STKM13B | ||||||
| STKM13C | ||||||
| STKM14A | ≤0.30 | ≤0.35 | 0.30-1.00 | ≤0.040 | ≤0.040 | |
| STKM14B | ||||||
| STKM14C | ||||||
Mechanical Properties
| Standard | Steel Grade | Mechanical Properties | ||
| Tensile Strength MPa | Yield Strength MPa | Elongation % | ||
| JIS G3445 | STKM11A | ≥295 | / | ≥35 |
| STKM12A | ≥345 | ≥175 | ≥35 | |
| STKM12B | ≥390 | ≥275 | ≥25 | |
| STKM12C | ≥470 | ≥355 | ≥20 | |
| STKM13A | ≥375 | ≥215 | ≥30 | |
| STKM13B | ≥440 | ≥305 | ≥20 | |
| STKM13C | ≥510 | ≥380 | ≥15 | |
| STKM14A | ≥410 | ≥245 | ≥25 | |
| STKM14B | ≥500 | ≥355 | ≥15 | |
| STKM14C | ≥550 | ≥410 | ≥15 | |
