304 Stainless Steel: Properties and Applications

By Coco

What is 304 Stainless Steel?

304 stainless steel is one of the most widely used austenitic stainless steel grades, known for its excellent corrosion resistance, high strength, and good weldability. It typically contains 18% chromium and 8% nickel, providing durability and resistance to oxidation and general corrosion. Common applications include kitchen equipment, chemical processing, and architectural structures.

304L Stainless Steel

304L is a low-carbon version of 304 stainless steel, with a maximum carbon content of 0.03%. The reduced carbon minimizes the risk of carbide precipitation during welding, improving corrosion resistance in welded components. It is often used for storage tanks, piping systems, and heat exchangers.

304H Stainless Steel

304H is a high-carbon version of 304 stainless steel, with a minimum carbon content of 0.04%. The increased carbon enhances high-temperature strength, making it suitable for boilers, heat exchangers, and industrial furnaces.

Sample product made from 304 stainless steel

Specification Standard for 304 Stainless Steel

	Specification Standard	Designation	Description
304	JIS	JIS SUS304	Sourcing products are used in food, medical, chemical, electronic industry, furniture decoration and other industries.
	ASTM	ASTM A240ASTM A276 ASTM A312 ASTM A240/240M 08
	EN	EN 10088-1EN 10217-7
	ISO	ISO 15510ISO 4955
304L	JIS	JIS G4303JIS G4304 JIS G4305	Making deep-drawing molding parts and acid transmission pipes, containers, structural parts, etc. It can also manufacture non-magnetic, low-temperature equipment and parts.
	ASTM	ASTM A240/240M 08
	EN	EN 10088-1EN 10095
	GB/T	GB/T 20878-2007GB/T3280-2015 GB/T4237-2015 GB/T24511-2017
304H	JIS	JIS G4303JIS G4311 JIS G4305	Mainly used in large boiler super heater, reheater, steam piping, petrochemical heat exchangers and other fields.
	ASTM	ASTM A240/240M 08
	GB/T	GB-T 24511-2017

304, 304L and 304H Stainless Steel Chemical Composition

Grade	C	Si	Mn	P	S	Cr	Ni
304	≤0.08	≤0.08	≤2.0	≤0.045	≤0.03	18.0～20.0	8.0～10.5
304L	≤0.03	≤1.00	≤2.00	≤0.045	≤0.030	18.00～20.00	8.00～12.00
304H	0.04-0.10	≤1.00	≤2.00	≤0.045	≤0.030	18.00～20.00	8.00～11.0

304, 304L and 304H Stainless Steel Corrosion Resistance

304 stainless steel contains 18% chromium (Cr) and 8% nickel (Ni) for good corrosion resistance. It is oxidation resistant in oxidizing environments and resists moderate organic acids such as acetic acid and reducing acids such as phosphoric acid.

304L Stainless Steel is a lower carbon version of 304 Stainless Steel, with a tightly controlled carbon content of less than 0.03%. This low carbon design significantly reduces the risk of intergranular corrosion, which improves the corrosion resistance of the stainless steel after welding and in long-term use.

304H stainless steel is a high-carbon version of 304 stainless steel, which typically has a carbon content of 0.04% to 0.1%. While 304H also has better corrosion resistance, it may have slightly less corrosion resistance than 304 stainless steel due to the increased carbon content.

In most corrosive environments, 304, 304L, and 304H perform equally well. However, in environments sufficient to cause intergranular corrosion in welded and heat-affected zones, 304L alloy is preferred because its low carbon content helps resist intergranular corrosion. The higher the carbon content, the lower the corrosion resistance of stainless steel and the more prone to rust, so the corrosion resistance of 304L is relatively good, while 304H due to the high carbon content, corrosion resistance is relatively weak.

Case Study

A precision machine tool manufacturer faced challenges in selecting suitable materials for key components during an equipment upgrade. Hengke Metals provided a tailored 304-series stainless steel solution: standard 304 for exterior parts to balance corrosion resistance and appearance, 304L for welded frame structures to prevent intergranular corrosion, and 304H for high-temperature cutting fluid systems to ensure stability under heat.

Throughout the project, Hengke’s materials engineers maintained close communication with the client, refining formulations based on actual operating conditions. After implementation, the client experienced improved equipment stability, longer maintenance intervals, and corrosion-free performance even in humid environments. This case highlights the versatility of the 304 stainless steel series and Hengke Metals’ expertise in delivering customized, application-driven material solutions.