What Is JIS G3454?
JIS G3454 is a Japanese Industrial Standard covering carbon steel pipes intended mainly for pressure service, typically at temperatures up to 350C (about 660F). It defines two material grades, STPG370 and STPG410, where STPG stands for steel tube for pressure use, and the number indicates the minimum tensile strength in megapascals. The pipes may be manufactured as seamless or electric-resistance-welded, and are widely used in steam, water, oil and gas piping systems in power plants, factories, ships and buildings.
Grades and Chemical Composition
The two grades differ mainly in carbon and manganese content, which give STPG410 a higher strength level. Commonly published composition limits for JIS G3454 pipe are shown below.
| Element (%) | STPG370 | STPG410 |
|---|---|---|
| Carbon (C), max | 0.25 | 0.30 |
| Silicon (Si), max | 0.35 | 0.35 |
| Manganese (Mn) | 0.30 - 0.90 | 0.30 - 1.00 |
| Phosphorus (P), max | 0.035 | 0.035 |
| Sulfur (S), max | 0.035 | 0.035 |
Mechanical Properties
Typical mechanical property requirements are listed below. Elongation values vary with wall thickness and test piece form, so the standard tables should be consulted for a specific size.
| Property | STPG370 | STPG410 |
|---|---|---|
| Tensile strength, min | 370 MPa | 410 MPa |
| Yield point, min | 215 MPa | 245 MPa |
| Elongation, min | 25% | 21% |
Available Sizes and End Finishes
JIS G3454 pipe is commercially supplied over a broad dimensional range, commonly from about 20 mm to 800 mm outside diameter with wall thicknesses from 3 mm to 150 mm, covering the standard schedule series used for pressure piping. End finishes include plain ends, beveled ends for butt welding, and threaded ends with plastic caps for protection. The exact size range available from a mill depends on the manufacturing process: seamless pipe covers the full range, while welded pipe is generally produced in the smaller and medium diameters.
Manufacturing and Testing
Pipes under JIS G3454 are produced from killed or semi-killed steel and may be seamless or electric-resistance-welded. Each pipe is subjected to hydrostatic testing to verify pressure tightness, and flattening or bend tests are carried out on samples to check ductility. Dimensional inspection covers outside diameter, wall thickness, straightness and length. The standard also addresses heat treatment, marking, inspection documents and surface condition, giving a complete quality framework for pressure service.
How JIS G3454 Relates to Other Standards
STPG370 and STPG410 are broadly comparable in strength level to pressure pipe grades in other systems: STPG370 is often equated with ASTM A53 Grade A or A106 Grade A in general pressure service, and STPG410 with ASTM A106 Grade B. Exact equivalence does not exist because the standards differ in composition limits, testing details and tolerances, so substitution should always be confirmed against the project specification and the applicable pressure code.
Frequently Asked Questions
What does STPG stand for in JIS G3454?
STPG denotes steel tube for pressure use in the JIS designation system, and the number following it is the minimum tensile strength in MPa.
Can JIS G3454 pipe be used for high-temperature steam?
The standard is intended for pressure service at temperatures up to about 350C. Above this temperature, design stresses must be checked against the applicable code, and alloy grades may be required.
Is JIS G3454 pipe seamless or welded?
Both manufacturing routes are permitted under the standard. Seamless pipe is produced by hot finishing or cold drawing, and welded pipe by electric resistance welding with the weld subjected to inspection.
What is the difference between STPG370 and STPG410?
STPG410 has a higher minimum tensile strength, 410 MPa versus 370 MPa, achieved through slightly higher carbon and manganese content.
What end finishes are available for JIS G3454 pipe?
Plain ends, beveled ends for welding, and threaded ends with protective caps are commonly offered, depending on the connection method of the piping system.