JIS G3462 STBA26 Alloy Steel Seamless Boiler Tubes
JIS G3462 STBA26 Alloy Steel Tubes are higher temperature resistance or capacity corrosion, being widely used by petroleum, chemical engineering, boiler, heat exchanger and other power areas.

Description

JIS G3462 STBA26 Alloy Steel Boiler Tubes
JIS G3462 STBA26 Alloy steel boiler and heat exchanger tubes
Standard: JIS G3462
JIS G3462 STBA26 Alloy Steel Tubes are higher temperature resistance or capacity corrosion, being widely used by petroleum, chemical engineering, boiler, heat exchanger and other power areas.
JIS G3462 STBA26 alloy steel tube is not applicable for heating furnaces and heat exchangers for low temperature service.
JIS G3462 STBA26 Alloy steel boiler and heat exchanger tubes Quick Details
Type:Seamless Alloy Steel Pipe
Wall thickness(WT): 3.2mm——14 mm.
Outer diameter (OD): 19.05mm——168.3 mm
Length: 6M or specified length as required.
Ends: Plain End, Beveled End, Treaded
Method of Manufacture
The tubes of STBA26 shall be manufactured by seamless process.
Heat treatments 
Grade Heat treatment
STBA 26 Isothermal annealing, full annealing or normalizing followed by tempering
Remark
1. Low temperature annealing shall not be applied to the electric resistance welded steel tube.
2. The tempering temperature for STHA26 shall be 650˚ or higher
Chemical Composition
Standard Grade Chemical Composition Limits (%)
C Si Mn P S Cr Mo
JIS G3462 STBA26 ≤ 0.15 0.25-1.00 0.30-0.60 ≤ 0.030 ≤ 0.030 8.00-10.00 0.90-1.10
Mechanical Properties
Grade Tensile Property (N/mm2) Yield Point or Yield Strength (N/mm2) Elongation (%)
OD ≥ 20 mm 10 mm ≤ OD <20 mm OD <10 mm
NO. 11 Sample; NO. 12 Sample NO. 11 Sample NO. 11 Sample
Longitudinal Transverse Transverse
STBA26 ≥ 412 ≥ 206 ≥ 30 ≥ 25

The dimensional tolerances of tube shall be as follows:
(1)The tolerance on the outside diameter of the tube

Tolerances on Outside Diameter Unit: mm
Division of outside diameter Tolerances on outside diamete
 Hot finished seamless steel tube Cold finished seamless steel tube Electric resistance welded steel tube other than cold finished Cold  finished  electric resistance welded steel tube
Under 25 +0.4

-0.8

【0.10 【1.5 【0.10
25 or over to and excl. 40 【0.15 【0.20 【0.15
40or over to and excl. 50 【0.20 【0.25 【0.20
50 or over to and excl 60 【0.25 【0.30 【0.25
60 or over to and excl. 80 【0.30 【0.40 【0.30
80 or over to and excl. 100 【0.40 +0.40 【0.40
-0.60
100 or over to and excl.12 +0.4

-1.2

+0.40
-0.60
+0.40
-0.80
+0.40
-0.60
120 or over to and excl.160 +0.40
-0.80
+0.40
-1.00
+0.40
-0.80
160 or over to and excl.200 +0.4 +0.40 +0.40 +0.40
-1.8 -1.20 -1.20 -1.20
200 or over +0.4 +0.40 +0.40 +0.40
-2.4 -1.60 -1.60 -1.60
Note:For the tolerances on the outside diameter of electric resistance welded steel tube other than cold finished, if specially required by the purchaser, the tolerances on the outside diameter of cold finished steel tube may substitute.

(2)Tolerances on Wall Thickness and on Thickness Deviation

Tolerances Division of wall
thickness (mm)
Division of method of manufacture Hot finished seamless steel tube Cold finished seamless steel tube Electric resistance welded steel tube
Division of outside diameter (mm) Under 100 100 or over Under 40 40 or over Under 40 40 or over
Tolerances on wall thickness % Under 2 +0.4mm +22

0

+0.3 +18

0

0 0
2 or over to and excl. 2.4 +40 +20

0

+18

0

0
2.4 or over to or excl. 3.8 +35 +35
0 0
3.8 or over to or excl. 4.6 +33 +33
0 0
4.6 or over +28 +28
0 0
Tolerances  on
thickness disparity
%
Within 22.8 of wall thickness
Note:The “thickness deviation” means the ratio of the difference between the maximum and the minimum thickness of the wall measured in the same section to the ordered wall thickness and shall not be applied to the tube under 5.6 mm in wall thickness
Testing  items:
Chemical Analysis,  Tensile Test , Flattening test, Flaring test,  Reverse Flattening Test , Hydrostatic Test or Nondestructive Examination.