JIS G3455 Pipe Standard

Updated May 2026

JIS G3455 is a well⁃known Japanese industrial standard that establishes specifications for carbon steel pipes used for high⁃pressure applications at temperatures of 350°C or lower. These pipes, known for their robustness and durability, are essential for industries requiring safe and efficient high⁃pressure applications.

The pipes are subject to strict manufacturing processes and quality checks, support a three⁃party review to ensure the best solution for a project, and are classified into 3 material classes.

JIS G3455 specification

Steel pipes according to JIS G3455 are available in outside diameters from 15 to 660.4mm and wall thicknesses from 1 to 56.6mm. Depending on requirements, these pipes can be supplied in their finished state, cold⁃drawn, or after appropriate heat treatment.

Production Standard: JIS G3455
Manufacturing Processes: Hot Finished Seamless (SMLS)
Cold ⁃Finished Seamless (SMLS)
Outside Diameter: 10.3mm to 660.4mm (1/8in to 26in)
Wall Thickness: 1.7 to 64.2mm
Pipe Length: 6 meters to 12 meters.
Steel Grades: JIS G3455 STS370
JIS G3455 STS410
JIS G3455 STS470
Corrosion Prevention: Lacquer, Varnish, Oiling, Galvanizing.
End Processes: Square Cut, Bevelling, Threading, Grooving.
Further Processing: Welding, Bending, Hole Drilling, Punching, Swaging, Tapering, Flaring, Expanding.

Steel grades of JIS G3455 pipes

There are three different grades according to the JIS G3455 specification. Each grade is designed for different industrial requirements, ensuring an optimal solution for all operational processes.

STS370
STS410
STS480

Key features and applications of JIS G3455 pipes

Power Plants: Widely used for boiler pipes, superheaters, and steam distribution systems that undergo extreme conditions.
Industrial Piping: Handles the transport of high⁃pressure steam, water, oil, and gas in refineries and chemical plants.
Mechanical and Hydraulic Systems: Used in high⁃pressure hydraulic cylinders, fuel injection systems, and precision mechanical parts.
Shipbuilding: Utilized for high⁃pressure fluid lines, crude oil tanker loading pipes, and structural components.

Dimensions of steel pipes JIS G3455

DN		O.D.	Wall Thickness
DN	NPS	MM	SCH 40	SCH 60	SCH 80	SCH 100	SCH 120	SCH 140	SCH 160
6	1/8	10.5	1.7	–	2.4	–	–	–	–
8	1/4	13.8	2.2	–	3.0	–	–	–	–
10	3/8	17.3	2.3	–	3.2	–	–	–	–
15	1/2	21.7 a	2.8	–	3.7	–	–	–	4.7
20	3/4	27.2	2.9	–	3.9	–	–	–	5.5
25	1	34.0	3.4	–	4.5	–	–	–	6.4
32	1 1/4	42.7	3.6	–	4.9	–	–	–	6.4
40	1 1/2	48.6	3.7	–	5.1	–	–	–	7.1
50	2	60.5	3.9	–	5.5	–	–	–	8.7
65	2 1/2	76.3	5.2	–	7.0	–	–	–	9.5
80	3	89.1	5.5	–	7.6	–	–	–	11.1
90	3 1/2	101.6	5.7	–	8.1	–	–	–	12.7
100	4	114.3	6.0	–	8.6	–	11.1	–	13.5
125	5	139.8	6.6	–	9.5	–	12.7	–	15.9
150	6	165.2	7.1	–	11.0	–	14.3	–	18.2
200	8	216.3	8.2	10.3	12.7	15.1	18.2	20.6	23.0
250	10	267.4	9.3	12.7	15.1	18.2	21.4	25.4	28.6
300	12	318.5	10.3	14.3	17.4	21.4	25.4	28.6	33.3
350	14	355.6	11.1	15.1	19.0	23.8	27.8	31.8	35.7
400	16	406.4	12.7	16.7	21.4	26.2	30.9	36.5	40.5
450	18	457.2	14.3	19.0	23.8	29.4	34.9	39.7	45.2
500	20	508.0	15.1	20.6	26.2	32.5	38.1	44.4	50.0
550	22	558.8	15.9	22.2	28.6	34.9	41.3	47.6	54.0
600	24	609.6	17.5	24.6	31.0	38.9	46.0	52.4	59.5
650	26	660.4	18.9	26.4	34.0	41.6	49.1	56.6	64.2

Notes..
Dimensions are in millimeters unless otherwise indicated.
DN = Diameter Nominal
NPS = Nominal Pipe Size
MM = Millimeters
O.D. = Outside Diameter
W.T. = Wall Thickness

Chemical requirements of JIS G3455 pipes

Pipes conforming to JIS G3455 are subject to strict requirements regarding their chemical composition. Each grade is designed for optimal performance under high⁃pressure conditions, thus ensuring the suitability of the pipes for demanding environments.

Designation of Grade	C	Si	Mn	P	S
STS370	0.25 max.	0.10 to 0.35	0.30 to 1.10	0.035 max.	0.035 max.
STS410	0.30 max.	0.10 to 0.35	0.30 to 1.40	0.035 max.	0.035 max.
STS480	0.33 max.	0.10 to 0.35	0.30 to 1.50	0.035 max.	0.035 max.

Mechanical requirements of JIS G3455 pipes

Mechanical requirements are crucial for high⁃pressure pipes. Pipes conforming to JIS G3455, such as the STS 370 model, have a minimum tensile strength of 373 MPa and a yield strength of 216 MPa. These properties ensure that the pipes can withstand high pressures without compromising their structural integrity.

Mechanical requirements
Designation of Grade	Tensile Strength 1 MPa	Yield Point or Proof Stress 1 MPa	Elongation %
			Test pieces No.11 Test pieces No.12	Test pieces No.5	Test pieces No.4
			Parallel to pipe axis	Perpendicular to pipe axis	Parallel to pipe axis	Perpendicular to pipe axis
STS370	370 min.	215 min.	30 min.	25 min.	28 min.	23 min.
STS410	410 min.	245 min.	25 min.	20 min.	24 min.	19 min.
STS480	480 min.	275 min.	25 min.	20 min.	22 min.	17 min.

Manufacturing process for JIS G3455 SGP pipes

The manufacturing process of pipes is as follows:

Pipes are manufactured from deoxidized steel using the seamless process and are finished according to Table 1 below.
Pipes undergo the heat treatment as specified in Table 2 below. Heat treatments other than those listed in Table 2 are agreed upon between the buyer and the manufacturer.

The pipe ends are flat, unless otherwise specified. At the buyer's request, pipes may be finished with chamfered ends. The shape of these ends is determined in consultation between the buyer and the manufacturer. Pipes with a wall thickness of up to 22mm have the shape shown in the image, unless otherwise specified.

Table 1
Grade	Manufacturing method
STS370 STS410 STS480	MFG method Seamless: S	Finishing method Hot⁃finished: H Cold⁃finished: C	Designation Marking of symbol denoting the manufacturing method shall be in accordance with 12B.

Table 2
Grade	Hot-finished seamless steel pipe	Cold-finished seamless steel pipe
STS410 STS370	As manufactured. However, low temperature annealing or normalizing may be applied, as necessary.	Low temperature annealed or normalized
STS480	Low temperature annealed or normalized

Hydrostatic testing / non⁃destructive testing of JIS G3455 pipes

A hydrostatic test or the non⁃destructive test must be performed, and there is a choice between the two tests; if not specified by the buyer, this is left to the manufacturer.

Hydrostatic test: The pipe must be held under the specified minimum hydraulic test pressure for at least 5 seconds and then inspected to see if it has withstood the pressure without leakage.

Non⁃destructive testing: The non⁃destructive testing shall be performed in accordance with JIS G0582 or JIS G0583. When applying other non⁃destructive testing methods as specified in the Japanese industrial standard, the choice of test method shall be agreed upon between the buyer and the manufacturer.

Reference..
Japanese Industrial Standards