|
| Grade of Steel: JIS G 3445 Grade STKM 11 A, STKM 12 A, B, STKM 13 A |
Dimension tolerance: Outside Dimension
Size Range: OD 17.3 mm. - 50.8 mm. (max)
Thickness: 0.45 mm. - 20 mm. |
 |
Grade |
Designation |
Tensile Strength
Kgf/mm2
{N/mm2} |
Yield point or proof stress
Kgf/mm2
{N/mm2} |
Elongation % |
Flattening Strength |
Bending strength |
No.4
No.11
No.12
test pieces Longitudinal direction |
No.4
No.5
test pieces Transverse direction |
Distance between flat plates (H)
(D is outside dia. of the tube) |
Bend angle |
Inside
radius
(D is
outside
dia> of
the tube) |
Grade 11 |
A |
STKM 11 A |
30 min. {294} min. |
- |
35 min. |
30 min. |
1/2 D |
180° |
4 D |
B |
STKM 12 A |
35 min. {343} min. |
18 min. {177} min. |
35 min. |
30 min. |
2/3 D |
90° |
6 D |
Grade 12 |
A |
STKM 12 B |
40 min. {392} min. |
28 min. {275} min. |
35 min. |
20 min. |
2/3 D |
90° |
6 D |
B |
STKM 12 C |
48 min. {471} min. |
36 min. {353} min. |
20 min. |
15 min. |
- |
- |
- |
Grade 13 |
A |
STKM 13 A |
38 min. {373} min. |
22 min. {216} min |
30 min. |
25 min. |
2/3 D |
90° |
6 D |
TECHNICAL SPECIFATION REFERENCES
Round, Square, & Rectangular Hollow Sections
ASTM A-500 Specification
Excerpts from ASTM A-500 Specification |
| Tolerance in Outside Dimensions |
Largest Outside Dimension, across flats, inch (mm.) |
Tolerances, Plus and minus, inch (mm.) |
| 2 1/2 (63.5) and under |
0.020 (0.50) |
| Over 2 1/2 to 3 1/2 (63.5 to 88.9), include (Tolerances include allowance for convexity or concavity) |
0.025 (0.64) |
Tolerance in Wall Thickness |
Plus and minus 10% of nominal thickness, exclusive of weld area |
Tolerance in Length |
Plus 2 inch (50.8 mm.) and minus zero on ordered lengths. (This is standard tolerance).
If any closer tolerance is desired, please be sure to specify that in your inquries or orders). |
| Tolerance in Length |
Specified Dimension of Longest Side. Inch (mm.) |
Maximum Twist in 3 ft., in. |
Maximum Twist in 1 m. mm. |
1 1/2 (38.1) and under |
0.050 |
1.39 |
Over 1 1/2 to 2 1/2 (38.1 to 63.5), incl. |
0.062 |
1.72 |
Over 2 1/2 to 4 (63.5 to 101.6), incl. |
0.075 |
2.09 |
Chemical Composition
(Heat Analysis) |
|
ASTM A-500 Specification Grade A |
Manufacturer Standard |
Carbon, max., % |
0.26 |
0.26 |
Manganese, max., % |
- |
- |
Phosphorus, max., % |
0.04 |
0.04 |
Sulphur, max., % |
0.05 |
0.05 |
| Mechanical Properties |
|
ASTM A-500 Specification Grade A |
Thai Koon Steel Standard |
Tensile strength, |
45,000 |
2700 N/ mm^2 min. |
min, psi (MPa) |
(310) |
- |
Yield point, min., psi (MPa) |
39,000 (269) |
170 N/ mm^2 min. |
Elongation (Gauge length 2") |
|
20% min. |
|
|
