Spring wire temperature limits are useful for screening material choices, but they are not universal failure temperatures. Leeco Spring International publishes maximum working temperatures for named material families and specifications, including music wire, chrome silicon, stainless spring wire, and copper alloys. The chart below preserves those supplier values in Fahrenheit. A spring can lose load through stress relaxation before it breaks, so the actual design limit depends on stress and exposure time as well as alloy.

Selected spring-wire temperature limits

How to use this reference

First match the wire family and specification on the spring drawing or supplier certificate. The 250°F limit shown for ASTM A228 music wire is not a limit for every carbon spring steel, and the 475°F value shown for ASTM A401 chrome silicon belongs to that supplier’s listed material. The table also identifies the supplier’s 302/304 and 316 stainless entries as 570°F. These entries should not be averaged with other spring makers’ charts because stress level, duration, wire condition, and rating criteria can differ.

Temperature is only one selection factor. Corrosion resistance, fatigue life, load, spring rate, available wire size, manufacturing process, and cost may control the choice. Copper alloys such as phosphor bronze and beryllium copper can support electrical or corrosion requirements, but their mechanical properties differ from steel wire. The table’s maximum temperature does not indicate that one material is a drop-in replacement for another.

Worked screening example

Suppose a compression spring uses ASTM A228 music wire and sees a sustained 225°F environment. The Leeco chart lists 250°F as its maximum working temperature for music wire, so the material passes only a preliminary temperature screen. The 25°F margin is not a safety factor: the designer still needs the applied stress, time at temperature, allowable load loss, cycling, and atmosphere. If the required retained load is critical, ask the spring manufacturer for data at the actual stress and exposure duration or select a material with validated operating margin.

For a second comparison, Leeco lists 475°F for ASTM A401 chrome silicon. That higher source value does not by itself make chrome silicon a valid replacement. The spring rate can change with shear modulus, and a new wire may require redesign and verification of fatigue and force. Review the full specification and confirm that the supplier’s value applies to the proposed wire size and production condition.

Why some source rows are omitted

The supplier page labels this table a general design reference and asks readers to contact the company about the application. Two entries were omitted from this publication dataset pending confirmation: the page associates 17-7PH with a UNS number that identifies a different stainless grade, and it reports an unusually high 1,830°F value for Inconel 600. Excluding these rows avoids presenting an unresolved designation/value as a dependable design limit. The remaining entries are still supplier-specific and should be confirmed before use.

Common mistakes

Do not compare temperatures without checking material identity and wire standard. Do not assume short excursions and continuous service have the same effect. Do not treat a maximum chart value as a guaranteed load-retention point. Also check whether the spring is lubricated or coated where those materials are part of a contact assembly; their temperature limits may control before the wire itself.

This selected reference is based on Leeco Spring International’s materials chart. Ask the spring maker for a recommendation that names the actual alloy, wire size, stress, exposure duration, environment, and required retained load.

For a spring under load, compare operating temperature with the allowable load loss over the expected service life. A brief peak and a continuous soak are not equivalent conditions. Include the wire’s stress and the surrounding environment in the supplier inquiry.