Material affects strength, fatigue life, corrosion resistance and available finishing processes. A request that only says “spring steel” rarely provides enough information for a reliable recommendation.
Start with operating conditions
Define maximum load, working travel, cycle target, temperature, humidity, media exposure and conductivity before selecting a grade. A spring used indoors and one exposed to salt spray may need different materials even at the same dimensions.
Higher material strength alone does not guarantee longer life. Forming quality, heat treatment, surface condition and operating stress remain critical.
Typical material directions
Music wire is a common choice for high-strength precision springs at normal temperatures. SUS304 suits humid or mildly corrosive environments and appearance-sensitive parts, while its mechanical behavior differs from high-carbon steel. 65Mn is used for many load-bearing springs and clips when paired with suitable heat treatment and corrosion protection.
Battery contacts and conductive parts also require attention to contact resistance, plating and joining methods. Corrosion resistance is only one part of that decision.
Finishing cannot fix a wrong base material
Zinc, nickel, black oxide and passivation can improve protection or appearance, but they do not compensate for an unsuitable base material. High-cycle parts should also evaluate pretreatment, hydrogen embrittlement risk and dimensional effects.
What to include in an RFQ
Provide the environment, target cycles, critical load points, available space, preferred material and finish. If the grade is unknown, share the operating conditions so candidate materials can be proposed and validated with samples.