JIS G 3429 Seamless Automotive Steel Tubes for High Pressure Gas Cylinder

STEEL GRADE AND CHEMICAL COMPOSITIONS max %

Seel Grade

Class

C

Si

Mn

P

S

Ni

Cr

Mo

STH11

Manganese

Steel tube

0.50max

0.10-0.35

1.80max

0.035max

0.035max

-

-

-

STH12

0.30-0.41

0.10-0.35

1.35-1.70

0.030max

0.030max

-

-

-

STH21

Chrome-molybdenum

  steel tube

0.25-0.35

0.15-0.35

0.40-0.90

0.030max

0.030max

0.25max

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

0.25max

0.80-1.20

0.15-0.30

STH31

Nickel-molybdenum

Steel tube

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

Remark:1.Alloying elements not included in Table 2 may be added as required.

2.The chemical composition given in Table 2 shall be similarly applied when product analysis is required by the purchaser

Dimensional Tolerances

OD %

WT %

Tolerance allowance %

      L

±1

﹢30

0

20max

﹢30mm

Note: the tolerance is not available for WT＜5.6mmtubes