Whether music wire spring is “better” than a stainless steel spring depends entirely on the application’s specific requirements. They offer different advantages and disadvantages.
Music Wire (High Carbon Steel – ASTM A228):
- Pros: Very high tensile strength, excellent fatigue life, high elastic limit, relatively low cost, readily available. Often the strongest choice for a given wire diameter among common materials.
- Cons: Poor corrosion resistance (rusts easily), limited performance at elevated temperatures (typically below 250°F / 121°C), magnetic. Requires protective coating (e.g., zinc plating, oil) in most environments.
Stainless Steel Spring Wire (e.g., AISI 302, 304, 316, 17-7PH):
- Pros: Excellent corrosion resistance (main advantage), suitable for food grade, medical, and outdoor applications, better performance at higher or lower temperatures compared to music wire (depending on the grade), non-magnetic or weakly magnetic (austenitic grades like 304, 316).
- Cons: Generally lower tensile strength and fatigue life compared to music wire of the same size (except for high-strength grades like 17-7PH), higher cost, potentially lower elastic modulus (meaning slightly less stiffness for the same geometry).
Direct Comparison:
| Feature | Music Wire | Stainless Steel (e.g., 302/304) | Stainless Steel (e.g., 17-7PH) |
|---|---|---|---|
| Tensile Strength | Very High | Good | Very High |
| Fatigue Life | Excellent | Good | Very Good |
| Corrosion Resistance | Poor | Excellent | Good |
| Temperature Range | Limited | Good (Moderate High/Low) | Excellent (Higher Temp) |
| Cost | Low | Moderate | High |
| Magnetism | Magnetic | Non-Magnetic (when annealed) | Magnetic (after hardening) |
Conclusion:
- Choose Music Wire if maximum strength, fatigue life, and low cost are the priorities, and corrosion is not a concern or can be managed with coatings.
- Choose Stainless Steel (like 302/304/316) if corrosion resistance, non-magnetic properties (for austenitic grades), or operation in specific environments (food, medical) are essential, and slightly lower strength is acceptable.
- Choose High-Strength Stainless Steel (like 17-7PH) if you need a combination of high strength (approaching music wire) and good corrosion resistance, especially at elevated temperatures, and the higher cost is justifiable.
Neither is universally “better”; they serve different purposes effectively.
