JIS G3462 Alloy steel boiler and heat exchanger tubes

JIS G3462 specifies the alloy steel boiler tubes for exchanging heat on the inside and outside of the water tube,smoke tube superheater tubes,ect.

JIS G3462 Alloy steel boiler and heat exchanger tubes


Equipoutlet mainly produces different grades of alloy steel pipes, such as STBA12, STBA13, STBA20, STBA22, STBA23, STBA24, STBA25, STBA26, etc.

Molybdenum steel tube:STB12,STB13

Chromium-molybdenum steel tube:STB20,STB22,STB23,STB24,STB25,STB26

 The JIS G3462 boiler tube Size:

The Outer dimension is from 19.05 mm to 168.3 mm & wall thickness ranges from 3.0 mm to 14 mm. JIS G3462 alloy steel tube is not applicable for heating heat exchangers and furnaces for low temperature service.

Chemical  Composition:

  Grade Chemical  Composition %
C Mn P S Si Cr Mo
STBA12 0.10-0.20 0.30-0.80 ≤0.035 ≤0.035 0.10-0.50 0.45-0.65
STBA13 0.15-0.25 0.30-0.80 ≤0.035 ≤0.035 0.10-0.50 0.45-0.65
STBA20 0.10-0.20 0.30-0.60 ≤0.035 ≤0.035 0.10-0.50 0.05-0.08 0.45-0.65
STBA22 ≤0.15 0.30-0.60 ≤0.035 ≤0.035 ≤0.50 0.08-1.25 0.45-0.65
STBA23 ≤0.15 0.30-0.60 ≤0.030 ≤0.030 0.50-1.00 1.00-1.50 0.45-0.65
STBA24 ≤0.15 0.30-0.60 ≤0.030 ≤0.030 ≤0.50 1.90-2.60 0.87-1.13
STBA25 ≤0.15 0.30-0.60 ≤0.030 ≤0.030 ≤0.50 4.00-6.00 0.45-0.65
STBA26 ≤0.15 0.30-0.60 ≤0.030 ≤0.030 0.25-1.00 8.00-10.0 0.90-1.10


  1. OD refers to the outside diameter.
  2. The above table is only applicable for heat exchanger alloy steel pipes. The buyer can appoint the upper limit value of tensile strength. The upper limit value of tensile strength is the above shown value plus 147 N/mm2.
  3. For the alloy steel tube with the thickness of less than 8 mm, we use NO.12 sample for tensile test. The minimum elongation will be reduced by 1.5% from the table value when the thickness reduces 1 mm. The value ​​obtained will be rounded to an integer value according to JIS Z 8401 (a rounding method).
  4. When we take the electric resistance welded steel pipes for tensile test, we also choose NO.12 sample from the parts not containing welding seams.

Mechanical Proerties:

  Grade Mechanical Proerties
Tensile Strength (Mpa) Yield Strength(Mpa) Elongation(%)
STBA12 ≥382 ≥206 ≥30
STBA13 ≥412 ≥206 ≥30
STBA20 ≥412 ≥206 ≥30
STBA22 ≥412 ≥206 ≥30
STBA23 ≥412 ≥206 ≥30
STBA24 ≥412 ≥206 ≥30
STBA25 ≥412 ≥206 ≥30
STBA26 ≥412 ≥206 ≥30

Packing: Bare/bundles/crates/crate protection at the both sides of tubes or as per customers' requirements.
Painting: as requested.

The tubes shall be manufactured by seamless process, electric resistance welding process, or butt welding process, and those of other grades shall be manufactured by seamless process or electric resistance welding process. The tube shall be as manufactured or as cold-finished condition, or they shall be subjected to appropriate heat treatment.

The tubes shall be practically straight. and the two ends shall be at right angles to the axis of the tube. The tubes shall be free from defects detrimental to practical use.

Higher temperature resistance or capacity corrosion, end up being widely used by petroleum, chemical engineering, boiler, heat exchanger and other power areas. JIS G3462 alloy steel tube is not applicable for heating furnaces and heat exchangers for low temperature service.

Size Array of JIS G3462 Alloy Steel Pipe


JIS G3462 regulates the allowable size deviation of alloy steel pipes, but JST advanced rolling technology can effectively lessens the deviation range and inside the dimension of alloy steel tube better. We may also supply other sizes of pipes solution . customers' requirements, but ought to ensure these alloy steel pipes pursue IS G3462 standards.

In production process, there always exists flaw, scar, wrinkling, laceration, rolling burr and other defects on alloy steel tube. JST configures UNICORN ultrasonic joint inspection machine, automatic ultrasonic testing equipment, magnetic flux inspection machine and other styles of inspection machines. They can test our alloy steel pipes.

JST also employs professional surface inspectors who's able to test the inconspicuous defects on the lining and outside surface of alloy steel tubes. As mentioned by the defect characteristics, perform polishing, removal, repair when a series of processes.

Seamless pipe Specification, standard and identification

Seamless pipes are extensively applied for the nuclear device, gas, petrochemical, ship building and boiler industries. Seamless pipes dominates 65% of market share in Chinese boiler industry.


Our team are highly trained and experienced in servicing and producing all types of steel supplies. Whether you've got a large construction project, or need parts for industrial machinery, our team of steel fabrication consultants will ensure that your project is provided with the parts you need, when you need them.

Link exchange

Copyright © 2011 Sunny Steel Enterprise Ltd.  All Rights Reserved ICP No.:08010763