| Reference Meterial |
 JIS G3472 Electric Resistance Welded Carbon Steel Tubes for Automobile Structural Purposes |
|
| Table 1 Chemical Composition |
 |
Designation |
Chemical
composition % |
C |
Si |
Mn |
P |
S |
STAM 290 GA |
 0.12 |
0.35 |
0.60 |
0.035 |
0.35 |
STAM 290 GB |
STAM 340 G |
0.20 |
0.35 |
0.60 |
0.035 |
0.35 |
STAM 390 G |
0.25 |
0.35 |
0.30 ~ 0.90 |
0.035 |
0.35 |
STAM 440 G |
0.25 |
0.35 |
0.30 ~ 0.90 |
0.035 |
0.35 |
STAM 470 G |
STAM 500 G |
0.25 |
0.35 |
0.30 ~ 0.90 |
0.035 |
0.35 |
STAM 440 GA |
STAM 470 GA |
0.30 |
0.35 |
0.30 ~ 1.00 |
0.035 |
0.35 |
STAM 500 GA |
STAM 540 GA |
0.30 |
0.35 |
0.30 ~ 1.00 |
0.035 |
0.35 |
|
| Note: |
Class G... Tubes
used for general parts of automobile
structure
Class H... Tubes used for the parts
of automobile structure for which yield strength
is particularly required |
|
| |
Table 2 Mechanical Property |
|
Grade |
Destination |
Tensile
test |
Expandign
test |
Tensile
Strength kgf/mm2 (N/mm2) |
Yield
point or proof stress kgf/mm2 (N/mm2) |
Elongation
(%)
No.11 specimen |
Outside
diameter |
Grade G |
STAM 290 GA |
 30
(290) |
18
(175) |
40 |
1.25 D |
STAM 290 GB |
30
(290) |
18
(175) |
35 |
1.20 D |
STAM 340 G |
35
(340) |
20
(195) |
35 |
1.20 D |
STAM 390 G |
40
(390) |
24
(235) |
30 |
1.20 D |
STAM 440 G |
45
(440) |
31
(305) |
25 |
1.15 D |
STAM 470 G |
48
(470) |
33
(325) |
22 |
1.15 D |
STAM 500 G |
51
(500) |
36
(353) |
18 |
1.15 D |
Grade H |
STAM 440 GA |
45
(440) |
36
(355) |
20 |
1.15 D |
STAM 470 GA |
48
(470) |
42
(410) |
18 |
1.10 D |
STAM 500 GA |
51
(500) |
44
(430) |
16 |
1.10 D |
STAM 540 GA |
55
(540) |
49
(480) |
13 |
1.02
D |
|
| Note: |
For the tubes as
cold-finished condition, the elongation value
shall be 10% and over, and expanding test shall
not be
applied. |
|
| |
| Table 3 |
Tolerances on Outside Diameter Division |
|
Division |
Tolerances
on Diameter Division |
|
No. 1 |
Under 50 mm |
± 0.25 mm |
50 mm |
± 0.5 % |
|
No. 2 |
Under 50 mm |
± 0.20 mm |
80 mm > D 50 mm |
± 0.25 mm |
|
No. 3 |
Min 25 mm |
± 0.12 mm |
50 mm > D 25 mm |
± 0.15
mm |
|
| |
| Table 4 Tolerances on Wall Thickness |
Division |
Tolerances
on outside diameter |
|
No. 1 |
Under 3 mm |
± 0.30 mm |
3 mm |
± 10% |
|
No. 2 |
Under 1.6 mm
|
+0.20
mm
-0.15 mm |
2.3 mm>t 1.6 mm |
± 0.20 mm |
3 mm>t 2.3 mm |
± 0.25 mm |
3 mm |
± 8% |
|
No. 3 |
Under 2 mm |
± 0.10 mm |
2 mm |
± 5% |
|
| Note: |
- Tolerance No.3 shall apply to cold-finished
steel tubes (rod drawn) as a rule.
- The values shown in the table shall not
apply to weld zone.
|
|
| |
| Table 5 Tolerances on
Height of Inner Surface Bead |
Division |
Tolerances
on height of inner surface
bead |
No. 1 |
Minus side tolerance is not
allowed |
No. 2 |
Not specified |
|
No. 3 |
+ 0.45mm
0 |
No. 4 |
+ 0.25 mm
0 |
No. 5 |
+ 0.20 mm
- 0.10
mm |
No. 6 |
± 0.20
mm |
|
| |
| Table 6 Tolerances on outside
diameter |
Division |
Tolerances on
outside diameter |
|
No. 1 |
Under 50 mm |
± 0.5
mm |
50 mm |
± 1% |
|
No. 2 |
Under 50 mm |
± 0.25 mm |
50 mm |
± 0.5% |
|
No. 3 |
Under 25 mm |
± 0.12 mm |
25 mm D<40
mm |
± 0.15% |
40 mm D<50
mm |
± 0.18% |
|
| |
| Table 7 Tolerances on Wall
Thickness |
Division |
Tolerances on
outside diameter |
|
No. 1 |
Under 4 mm |
+0.6
mm
-0.5 mm |
4 mm |
+15%
-12.5% |
|
No. 2 |
Under 3 mm |
± 0.3
mm |
3 mm |
± 10% |
|
No. 3 |
Under 2 mm |
± 0.15 mm |
2 mm |
± 8% |
|
| |
