904L vs 316L stainless steel: key differences

904L vs 316L Stainless Steel: Key Differences for Buyers and Engineers

 

When selecting stainless steel for critical applications, especially those involving corrosion, strength, and aesthetics, two popular choices often emerge: 904L and 316L. Both are austenitic stainless steels, but they differ significantly in chemical composition, corrosion resistance, mechanical properties, and cost. In this guide, we compare 904L vs 316L stainless steel, answering common industry questions to help you make an informed material selection.

 

904L vs 316L Stainless Steel.pdf

 

What Is the Grade of 316L Equivalent To?

UNS S31603

EN 1.4404

JIS SUS316L

ASTM A240 / A312 (depending on form)

It is a low-carbon version of 316, offering excellent corrosion resistance, especially against chlorides and marine environments, and is widely used in food processing, chemical equipment, and medical applications.

Is 316L Better Than 904L?

Not necessarily - it depends on your application.

Property	316L	904L
Corrosion Resistance	Excellent (marine-grade)	Superior (acid and chloride resistance)
Nickel Content	~10–14%	~23–25%
Molybdenum Content	~2–3%	~4–5%
Chloride Resistance	Good	Excellent
Weldability	Very good	Good
Stress Corrosion Cracking	Moderate resistance	High resistance

Verdict: Choose 316L for general marine or industrial use. Choose 904L for aggressive environments involving sulfuric acid, chlorides, or higher temperature corrosion.

904L vs 316L Price

904L is significantly more expensive than 316L due to its higher alloy content, especially nickel and molybdenum.

Grade	Approx. Price (USD/kg)
316L	$4 – $8
904L	$10 – $20

904L vs 316L price tip: For cost-sensitive projects with moderate corrosion requirements, 316L is the practical choice. For extreme corrosion resistance, 904L offers long-term value despite higher upfront cost.

904L vs 316L ：Scratch Resistance

Both 904L and 316L are austenitic stainless steels, which means they are relatively soft compared to martensitic or duplex grades. However:

904L may be slightly more scratch-resistant due to its higher nickel content, which enhances toughness.

Surface finish (e.g., polished, brushed, bead-blasted) plays a bigger role than the alloy in scratch visibility.

In applications like luxury watches or visible surfaces, proper surface treatment is more critical than alloy selection alone.

904L vs 316L Hardness

Grade	Brinell Hardness (HB)	Rockwell B (HRB)
316L	~150–160 HB	~80 HRB
904L	~170–190 HB	~90 HRB

904L is slightly harder than 316L, offering better wear resistance under abrasive conditions, but still falls within the low to medium hardness range typical of austenitic stainless steels.

Which Should You Choose?

Criteria	Best Choice
Cost-effective general use	316L
Superior acid/chloride resistance	904L
High-nickel durability	904L
Medical or food-grade use	316L
Scratch & hardness sensitivity	904L (slightly better)