AISI 304 vs. AISI 316 Stainless Steel: Electrical Conductivity

When choosing between AISI 304 and AISI 316 stainless steel, many buyers focus on factors like corrosion resistance, strength, and weldability. However, another important consideration is electrical conductivity. This property can impact the material's performance in various electrical, electronic, and industrial applications. This guide explains the differences between AISI 304 and AISI 316 stainless steels in terms of electrical conductivity and how these differences affect their use in specific industries.

 

 

What is Electrical Conductivity?

Electrical conductivity refers to a material's ability to conduct electric current. In metals like stainless steel, electrical conductivity is primarily determined by the density of free electrons. Generally, materials with higher nickel and chromium content tend to have lower electrical conductivity because these elements increase the resistance of the material to the flow of electricity.

 

Electrical Conductivity in Stainless Steels

304 stainless steel is a popular austenitic grade with relatively lower electrical conductivity compared to other metals like copper or aluminum.

316 stainless steel is similar to 304, but it contains an additional 2–3% molybdenum, which further decreases its electrical conductivity.

Electrical Conductivity Comparison: AISI 304 vs AISI 316

Material	Electrical Resistivity (Ω·m at 20°C)	Electrical Conductivity (S/m)	% IACS*
Copper (annealed, C11000)	1.68 × 10−8	5.96 × 107	100%
Aluminum (AA1350)	2.82 × 10−8	3.55 × 107	61%
Brass (C26000, 70Cu-30Zn)	6.20 × 10−8	1.61 × 107	28%
AISI 304 (UNS S30400)	7.20 × 10−7	1.39 × 106	~2.3%
AISI 316 (UNS S31600)	7.40 × 10−7	1.35 × 106	~2.3%
AISI 430 (ferritic)	6.00 × 10−7	1.67 × 106	~2.8%

Note: Both 304 and 316 stainless steels have relatively poor electrical conductivity compared to metals like copper and aluminum. This is due to the high alloy content, which is designed to improve corrosion resistance rather than electrical performance.

 

What is the electrical conductivity of 304 stainless steel?

AISI 304 has an electrical conductivity of approximately 1.39 × 106 S/m at 20°C, corresponding to a resistivity of 0.72 µΩ·m (72 µΩ·cm). This is roughly 2.3% of copper's conductivity. Per ASM MatWeb data for annealed 304 sheet, the resistivity value is 7.2 × 10−5 ohm-cm .

 

Is 316 more or less conductive than 304?

The electrical conductivity of 316 is slightly lower. Its resistivity is 0.74 µΩ·m (compared to 0.72 µΩ·m for 304), corresponding to a conductivity of approximately 1.35 × 10⁶ S/m-about 2.9% lower than that of 304. This difference stems from the 2%–3% molybdenum content in 316, which introduces additional electron scattering centers into the crystal lattice. In engineering practice, however, this difference is negligible.

Does cold working change the electrical properties of 304 or 316?

Yes, though the change is minimal. Cold working increases dislocation density and can induce the formation of strain-induced martensite in metastable austenitic steel grades. This results in a 1% to 5% increase in electrical resistivity, depending on the degree of cold work.
A more significant effect is that cold working induces magnetic permeability (i.e., magnetism) in these steel grades, with Type 304 being more susceptible to this than Type 316. For applications requiring stable, predictable electrical conductivity or non-magnetic properties, material in the annealed condition-compliant with ASTM A240 standards (i.e., solution annealed at 1040–1120°C followed by rapid cooling)-should be specified.

 

When to Choose AISI 304 or AISI 316 Based on Conductivity?

While both AISI 304 and AISI 316 are suitable for applications with lower conductivity requirements, the choice between them depends primarily on the application environment.

AISI 304 Stainless Steel: Suitable for indoor environments where conductivity is not critical but corrosion resistance remains important. Application examples: Kitchen appliances, food processing equipment, building components, and industrial storage tanks.

AISI 316 Stainless Steel: Best suited for corrosive environments (e.g., marine, chemical, and pharmaceutical industries), where corrosion resistance is more important than conductivity.

Application examples: Marine equipment, pharmaceutical machinery, chemical processing, and marine hardware.

 

Why Choose Gnee for Your Stainless Steel Supply
Gnee Stainless Steel is a leading global supplier of AISI 304 and AISI 316 stainless steel products, including plates, sheets, coils, tubes, and bars.
Why Gnee Stainless Steel:
✅ Global Reach: Over 18 years of experience supplying to more than 60 countries.
✅ High-Quality Products: ISO 9001, SGS, and BV certified products.
✅ Fast Delivery: Delivery within 7–15 days from stock.
✅ Competitive Pricing: Direct factory pricing for both 304 and 316 stainless steels.
✅ Customization: Cut-to-size, polishing, cutting, and other services available.
Get a free quote for your specific AISI 304 or AISI 316 stainless steel needs today!
📧 Email: sales@gneestainless.com