You are working on an international project. The engineer specifies ASTM A240. The fabricator asks for JIS G4305. You need to know if they are the same material.

ASTM (American) and JIS (Japanese) are different standards for stainless steel sheets. They often have equivalent grades, but the designations and some requirements differ. ASTM A240 304 is equivalent to JIS G4305 SUS304. The chemical composition and mechanical properties are very similar, but dimensional tolerances and testing requirements may vary. ASTM A240 explained (incl. JIS G4305)

I have supplied stainless steel sheets to both ASTM and JIS standards. A customer in the US required ASTM A240. A customer in Southeast Asia required JIS G4305. Let me walk you through the differences and equivalents. Stainless steel grades comparison (ASTM, JIS, EN, etc.)

What is the JIS SS400 equivalent to ASTM?

SS400 is a JIS standard for carbon steel structural shapes, not stainless steel. Its ASTM equivalent is ASTM A36 (carbon steel structural). JIS SS400 equivalent ASTM A36

For stainless steel sheets, the JIS standard is G4305. The JIS SUS304 is equivalent to ASTM A240 304. The JIS SUS316 is equivalent to ASTM A240 316. SUS304 and SUS316 equivalents (ASTM A240)

Carbon Steel Equivalents (Not Stainless)

Let me clarify the equivalents for carbon steel standards.

JIS SS400 – Carbon Steel

Property	Value
JIS Standard	SS400 (JIS G3101)
ASTM Equivalent	A36
Material Type	Carbon steel (not stainless)
Tensile strength	400-510 MPa
Yield strength	245 MPa min

Stainless Steel Equivalents (JIS G4305)

JIS Grade	ASTM Equivalent	EN Equivalent
SUS304	A240 304	1.4301
SUS304L	A240 304L	1.4307
SUS316	A240 316	1.4401
SUS316L	A240 316L	1.4404
SUS430	A240 430	1.4016

My Experience
A customer asked for SS400 stainless. I explained that SS400 is carbon steel, not stainless. They meant SUS304. Stainless steel grade equivalents (JIS, ASTM, EN)

What is the difference between ASME and JIS?

ASME (American Society of Mechanical Engineers) is a standard for pressure vessels and boilers. JIS (Japanese Industrial Standards) is the national standards system for Japan covering all industries, including steel.

For stainless steel sheets, ASTM is the material standard. ASME adopts ASTM material standards for pressure vessel use (ASME SA-240 is identical to ASTM A240). JIS uses different designation systems (e.g., SUS304 vs 304). ASME vs JIS vs ISO engineering standards

ASME vs JIS Comparison

Let me compare ASME and JIS for stainless steel sheets.

ASME (American)

Property	Value
Scope	Pressure vessels, boilers
Material standard	SA-240 (adopts ASTM A240)
Grade designation	304, 316, etc.
Dimensional tolerance	ASTM A480
Common in	North America, international projects

JIS (Japanese)

Property	Value
Scope	All industries (steel, automotive, electronics)
Material standard	G4305 (cold-rolled sheet), G4304 (hot-rolled plate)
Grade designation	SUS304, SUS316, etc.
Dimensional tolerance	JIS G4313 or other JIS standards
Common in	Japan, Southeast Asia, some international

Key Differences for Stainless Steel Sheet

Feature	ASME (ASTM)	JIS
Grade designation	304	SUS304
Chemical composition limits	Slightly different	Slightly different
Dimensional tolerances	ASTM A480	JIS G4313
Acceptance criteria	Varies	Varies

My Experience
For a pressure vessel, we used ASME SA-240 304L. For a general fabrication project in Southeast Asia, we used JIS G4305 SUS304. SA240‑304 vs SUS304 comparison

What is the JIS standard for stainless steel sheets?

The JIS standard for stainless steel sheets is JIS G4305 (cold-rolled stainless steel sheets and strips) and JIS G4304 (hot-rolled stainless steel plates and sheets). JIS G4304 & G4305 overview

JIS G4305 covers cold-rolled stainless steel sheets with thickness from 0.3mm to 6mm. It specifies grades (SUS304, SUS316, SUS430, etc.), chemical composition, mechanical properties, and dimensional tolerances. It is the most common JIS standard for stainless steel sheets. JIS G4305 specification details

JIS G4305 Specifications

Let me provide the key specifications of JIS G4305.

Grades Covered

Grade	Type	Equivalent ASTM
SUS304	Austenitic	304
SUS304L	Austenitic	304L
SUS316	Austenitic	316
SUS316L	Austenitic	316L
SUS430	Ferritic	430

Chemical Composition (SUS304 vs ASTM 304)

Element	SUS304 (JIS)	304 (ASTM)
Carbon	0.08% max	0.08% max
Manganese	2.00% max	2.00% max
Chromium	18.0-20.0%	18.0-20.0%
Nickel	8.0-10.5%	8.0-10.5%

Mechanical Properties (SUS304)

Property	Value
Tensile strength	520 MPa min
Yield strength	205 MPa min
Elongation	40% min

Dimensional Tolerances (JIS G4313)

Thickness (mm)	Tolerance (mm)
0.3-0.5	±0.05
0.5-1.0	±0.06
1.0-2.0	±0.08
2.0-3.0	±0.10
3.0-4.0	±0.12

My Experience
For a customer in the Philippines, we supplied JIS G4305 SUS304 sheet. The standard was specified in their project documents. Stainless steel JIS G4305 technical data

What are the 4 types of stainless steel?

The four main types of stainless steel are austenitic, ferritic, martensitic, and duplex. Each has different properties, corrosion resistance, and applications. The four types of stainless steel

Austenitic (304, 316) is non-magnetic, has excellent corrosion resistance, and is the most common. Ferritic (430) is magnetic, has good corrosion resistance, and lower cost. Martensitic (410, 420) is magnetic, heat treatable, and used for wear resistance. Duplex (2205) combines austenitic and ferritic properties for high strength and excellent corrosion resistance. Understanding stainless steel: types, grades & applications

The 4 Types Explained

Let me explain each type of stainless steel.

Austenitic Stainless Steel

Property	Value
Grades	304, 304L, 316, 316L, 321
Structure	Face-centered cubic (FCC)
Magnetic	Non-magnetic (annealed)
Corrosion resistance	Excellent
Heat treatable	No (only cold work)
Applications	Food equipment, chemical, marine

Ferritic Stainless Steel

Property	Value
Grades	409, 430, 439, 446
Structure	Body-centered cubic (BCC)
Magnetic	Magnetic
Corrosion resistance	Good
Heat treatable	No
Applications	Automotive exhaust, appliances

Martensitic Stainless Steel

Property	Value
Grades	410, 416, 420, 440C
Structure	Body-centered tetragonal
Magnetic	Magnetic
Corrosion resistance	Fair to good
Heat treatable	Yes (hardening)
Applications	Cutlery, valves, shafts

Duplex Stainless Steel

Property	Value
Grades	2205, 2304, 2507
Structure	Austenitic + ferritic (50/50)
Magnetic	Magnetic
Corrosion resistance	Excellent (superior to 316)
Heat treatable	No
Applications	Offshore, marine, chemical

My Experience
For a food plant, we used austenitic 304. For a knife blade, we used martensitic 420. For an offshore component, we used duplex 2205. Stainless steel grades and families explained

Conclusion

ASTM A240 304 is equivalent to JIS G4305 SUS304. ASME adopts ASTM standards; JIS is Japan's national standard. JIS G4305 covers cold-rolled stainless steel sheets. The four stainless steel types are austenitic, ferritic, martensitic, and duplex. JIS G4305 & ASTM A240 comparison Understanding stainless steel: types, grades & applications