This stainless steel flat spring is designed for precision applications requiring stable elasticity and durability. It is widely used in electronic and industrial components, with customizable thickness, shape, and material to meet OEM requirements.

Stainless Steel Spring Properties: SUS301 vs SUS304 for Precision Parts

When designing precision metal components, choosing the right stainless steel grade is critical. While both SUS301 and SUS304 are standard austenitic stainless steels, they behave very differently when formed into springs or flat contacts. At NKEYTO, we help clients navigate these differences to ensure their Stainless Steel Flat Spring Sheets perform exactly as intended.

SUS301: The Choice for High Elasticity

SUS301 is the preferred material for applications requiring high strength and superior elasticity. It is characterized by a high work-hardening rate, meaning it becomes significantly stronger and harder as it is cold-rolled or formed.

• High Elastic Limit: SUS301 can withstand significant deflection and return to its original shape, making it ideal for spring contacts, battery clips, and shielding cans.
• Magnetic Properties: Unlike SUS304, SUS301 often becomes slightly magnetic after cold working, which is a consideration for certain electronic applications.
• Typical Use: Battery contacts, EMI shielding springs, and mechanical clips where "springiness" is the primary requirement.

SUS304: The Choice for Corrosion Resistance

SUS304 is the most widely used stainless steel in the world. While it has a lower work-hardening rate than SUS301, it offers superior corrosion resistance due to its higher Nickel and Chromium content.

• Chemical Stability: It resists oxidation and corrosion better than SUS301, making it suitable for harsh environments or medical applications.
• Formability: It is easier to weld and form into complex shapes without cracking, though it does not achieve the same high hardness levels as SUS301 in the fully hard state.
• Typical Use: Medical device components, food processing parts, and structural brackets where corrosion resistance is more critical than extreme spring force.

Comparison Table: SUS301 vs SUS304

Heat Treatment & Hardness Control

At NKEYTO, we don't just supply metal; we engineer its properties. The hardness and elasticity of stainless steel springs are controlled through Cold Rolling and Heat Treatment (Annealing).

We can supply materials in various tempers to match your design needs:

• 1/4 Hard: Soft and ductile, suitable for deep drawing.
• 1/2 Hard: A balance of formability and strength.
• 3/4 Hard: Good spring properties for moderate flexing.
• Full Hard (FH): Maximum hardness and strength, ideal for flat springs that require high restoring force.

NKEYTO Custom Manufacturing

Whether you need the high snap of SUS301 or the durability of SUS304, NKEYTO can process these materials via Chemical Etching or Precision Stamping. We ensure the material state (annealed or hardened) matches your performance requirements perfectly.

Contact Us

Get the right steel for your spring application. Contact Luna today.

WhatsApp: 12132219094
Company: NKEYTO (Shenzhen Xintu Precision Hardware Co., Ltd.)
Location: Shenzhen, China

Frequently Asked Questions (FAQ)

Q1: Which is better for a battery contact spring, SUS301 or SUS304?
A: SUS301 is generally better for battery contacts because it has a higher elastic limit. This ensures the spring maintains constant pressure against the battery, preventing power interruptions even if the device is dropped or vibrated.

Q2: Can SUS301 be used in outdoor environments?
A: Yes, SUS301 has good corrosion resistance and is suitable for many outdoor applications. However, if the environment is highly corrosive (e.g., near saltwater), SUS304 or SUS316 would be a safer choice.

Q3: What does "Full Hard" mean?
A: "Full Hard" refers to a stainless steel sheet that has been cold-rolled to its maximum hardness (typically HV 400+ for SUS301). It is very stiff and springy, making it perfect for flat springs but difficult to bend into complex shapes without cracking.

Q4: Do you supply material certifications?
A: Yes, we provide Material Test Reports (MTRs) and certifications (such as SGS/RoHS) to verify the chemical composition and mechanical properties of the stainless steel we use.