JIS G3429 seamless steel tubes
JIS G3429 seamless steel tubes are used for the manufacture of seamless steel gas cylinders specified in JIS B 8230 and JIS B 8241.
JIS G3429 manufacture method:
(1) Manufactured in open-hearth furnace or electric furnace(Seamless).
(2) The tubes is manufactured with no heat treatment.
Chemical Composition:
| Class | C | Si | Mn | P | S | Ni | Cr | Mo |
|---|---|---|---|---|---|---|---|---|
| STH11 | 0.50 max | 0.10~0.35 | 1.80 max | 0.035max | 0.035max | - | - | - |
| STH12 | 0.30~0.41 | 0.10~0.35 | 1.35~1.70 | 0.030max | 0.030max | - | - | - |
|
STH21 |
0.25~0.35 |
0.15~0.35 |
0.40~0.90 |
0.030max |
0.030max |
0.25 max |
0.80~1.20 |
0.15~0.30 |
|
STH22 |
0.33~0.38 |
0.15~0.35 |
0.40~0.90 |
0.030max |
0.030max |
0.25 max |
0.80~1.20 |
0.15~0.30 |
| STH31 | 0.35~0.40 | 0.10~0.50 | 1.20~1.50 | 0.030max | 0.030max | 0.50~1.00 | 0.30~0.60 | 0.15~0.25 |
Tolerances：
| Tolerance on outside diameter | Tolerance on wall thickness | Tolerance on wall thickness disparity | Tolerance on length |
|---|---|---|---|
| 1% | +30% | Within 20% of the nominal wall thickness |
>+30mm
0 |
