JIS–G–3445 — Carbon Steel Tubes for Machine Structural Purposes

JIS–G–3445 is a Japanese Industrial Standard specifying carbon steel tubes for machine structural purposes. These tubes are used in mechanical and structural applications requiring precise dimensional tolerances and consistent mechanical properties.

Carbon Steel Tubes for Machine Structural Purposes — Japanese Standard (JIS–G–3445) ASTM A423, Grade-1 or ASTM 714 — Corten Air Heater Tubes
Specification Grade Chemistry Rm min.
kgf/mm²
N/mm²
Re min.
kgf/mm²
N/mm²
Bend Test
D ≤ 50 mm
'A' Elongation % min
(Longitudinal) D > 40 mm
Tolerances as per Division 3
C% Mn% Bend
Angle°
Bend
Diameter
t ≤ 1mm 1 < t ≤ 2 2 < t ≤ 3 3 < t ≤ 4 On Outside
Diameter
On
Thickness
JIS :
G–3445–1983
STKM–11A 0.12
max.
0.6
max.
30
294
180 4D 24 26 28 29 D < 25 mm
± 0.12 mm
t < 2 mm
± 0.15 mm
STKM–12A 35
343
18
177
90 6D 24 26 28 29 25 ≤ D < 40 mm
± 0.15 mm
t > 2 mm
± 8%
STKM–12B 0.2
max.
0.6
max.
40
392
28
275
90 6D 14 16 18 19 40 ≤ D < 50 mm
± 0.18 mm
STKM–12C 48
471
36
353
10 11 12 14 50 ≤ D < 60 mm
± 0.20 mm
STKM–13A 38
373
22
216
90 6D 20 21 22 24 60 ≤ D < 70 mm
± 0.23 mm
STKM–13B 0.25
max.
0.3 /
0.9
45
441
31
304
90 6D 10 11 12 14 70 ≤ D < 80 mm
± 0.25 mm
STKM–13C 52
510
39
382
4 6 8 9
Rm: Tensile strength     Re: Yield stress     D: Outside diameter     t: Wall thickness
Supply

Available in all STKM grades conforming to JIS–G–3445 : 1983. Custom sizes and lengths supplied on request to meet specific machine structural requirements.