sus304 vs ss304 Material : key differences

If you are sourcing 304 stainless steel for industrial, chemical, food, or construction applications, you may have come across the terms SUS304 and SS304. Understanding the key differences, material standards, mechanical properties, and applications is crucial for making the right purchasing decision.
This guide will provide a complete comparison, including data sheets, advantages, common questions, and procurement considerations.

 

What is the difference between SS and SUS304?
SUS304: Japanese designation according to JIS G4304 / G4305. Widely used in Japan and Asia.
SS304: Common international term used for stainless steel 304, often referring to ASTM A240 / A276 standards.
Both are austenitic stainless steels with excellent corrosion resistance, high ductility, and good weldability. The main differences are naming conventions and minor regional standard variations, not chemical composition.

 

 

Are SUS304 and SS304 the same?
Yes, both are 304 austenitic stainless steel. SUS304 is the Japanese JIS designation, while SS304 is the international term.

 

What is the equivalent material of SUS304 stainless steel?

Grade	UNS No	Old British		Euronorm		Swedish SS	Japanese JIS
		BS	En	No	Name
304	S30400	304S31	58E	1.4301	X5CrNi18-10	2332	SUS 304
304L	S30403	304S11	-	1.4306	X2CrNi19-11	2352	SUS 304L
304H	S30409	304S51	-	1.4948	X6CrNi18-11	-	-

 

sUS 304 vs sS304: Chemical Composition

Temperature Range
Steel Grade	SUS304	SS 304
C ≤	0.08	0.07
Si ≤	1.00	0.75
Mn ≤	2.00	2.00
P ≤	0.045	0.045
S ≤	0.030	0.03
Cr	18.00-20.00	17.5-19.5
Ni	8.00-10.50	8.0-10.5

 

sUS 304 vs sS304: Physical Properties

	Density(g/cm3)	Melting point (℃)	Specific heat (J/kg·℃)	Electrical resistivity (μΩ·m) (20℃)	Thermal expansion (10-6/K)	Thermal conductivity (W/m·K)
SUS304 Material Physical Properties ≤	7.93	1,400-1,450	460-502	0.73	16.3 (20-100℃) 17.8 (20-300℃) 18.4 (20-500℃)	16.8 (100℃)
SS 304 Material Physical Properties	7.93 g/cm3	1398-1454 ℃	500 J/(Kg·K) at 0-100℃	0.73 μΩ·m (20℃)	17.2 (0-100℃) 17.8 (0-300℃ 18.4 (0-500℃)	16.3 (100 ℃)

SUS 304 Vs SS304：Chemical Composition
Chemically identical in most cases; minor differences in sulfur or phosphorus content may exist depending on local standards.

 

SUS 304 Vs SS304：Surface & Finish
Both are available in 2B, BA, No.4, Mirror Polished,SUS304 sometimes preferred for domestic appliances in Japan, while SS304 is often used in export and industrial projects.

 

SUS 304 Vs SS304：Corrosion Resistance & Durability
SUS304 and SS304 are essentially the same material, with SUS being the Japanese designation and SS (or AISI) being the American designation for the same grade of stainless steel. Their corrosion resistance and durability are virtually identical, offering excellent resistance to corrosion in most environments but with susceptibility to chloride-rich environments.

SUS 304 Vs SS304：Machinability & Weldability
SUS304 and SS304 have nearly identical machinability and weldability, as they are essentially the same austenitic stainless steel alloy with slight nomenclature differences based on their originating standards (Japanese JIS for SUS304 and American ASTM for SS304). For practical purposes, their machinability and weldability are interchangeable, though slight differences in trace elements may affect performance in specific, highly demanding applications.

 

Can SUS304 / SS304 be used in marine environments?
They resist corrosion in freshwater and mildly saline environments, but for prolonged exposure to seawater, 316L may be a better choice.

 

Can SUS304 / SS304 be welded?
Yes, both grades have excellent weldability, especially in annealed condition.

 

SUS304 / SS304 stainless steel price per kg

Product Type	Size / Form	Approx. Price (USD/kg)	Remarks
SUS304 / SS304 Sheet	0.5 – 3 mm	$3.5 – $4.5	2B / BA finish
SUS304 / SS304 Strip	0.3 – 2 mm	$3.2 – $4.2	Cold-rolled
SUS304 / SS304 Plate	4 – 50 mm	$4.5 – $6.5	Hot-rolled
SUS304 / SS304 Pipe / Tube	OD 6 – 200 mm	$5 – $8	Seamless / Welded

Tip for buyers: Purchase from certified suppliers to ensure consistent quality, accurate thickness, surface finish, and MTC certificates.Email: info@gneestainless.com