Material is one of the first decisions on any spring drawing, and one of the easiest to get wrong. Choose music wire for a part that sees moisture, and it rusts. Choose stainless steel for a part that doesn’t need it, and you pay more for a spring that may also be weaker than the one it replaced.
This guide compares music wire vs stainless steel springs on the properties that matter to engineers and the costs that matter to purchasing. It covers strength, stiffness, temperature, corrosion, finishing and price, and closes with a simple decision checklist you can use before you send an RFQ.
The Short Answer
The choice between music wire vs stainless steel springs comes down to environment first and load second. Use music wire when the spring lives in a dry, protected, room-temperature environment and you want the most strength for the lowest cost. Use stainless steel when the spring will see moisture, chemicals, washdown, outdoor exposure or temperatures above about 250°F, or when a plated finish is not acceptable. Within stainless, type 302 is the general-purpose default, 316 is the choice for harsher corrosion, and 17-7 PH is the choice when you need stainless with near-music-wire strength or higher heat resistance.
What Is Music Wire?
Music wire is a high-carbon, cold-drawn spring steel made to ASTM A228. It is the most widely used spring material because it combines very high tensile strength, excellent fatigue life and a smooth, consistent surface at a low price. It is also widely available in fine sizes, which makes it a natural fit for small precision springs.
Its weakness is corrosion. Bare music wire will rust in humid air, so it usually ships with an oil coating or a protective finish such as zinc plating or black oxide. It is also limited to roughly 250°F, above which it begins to lose load.
What Is Stainless Steel Spring Wire?
Stainless spring wire covers several alloys. The most common is type 302 (often supplied as 302/304) to ASTM A313. It is cold drawn to spring temper, resists corrosion in most everyday environments, and handles temperatures up to about 550°F. Type 316 adds molybdenum for better resistance to chlorides and harsher chemicals, at the cost of lower strength. Type 17-7 PH is a precipitation-hardening stainless that reaches strength levels close to music wire after a post-coiling heat treatment, and it can be used up to about 650°F.
Music Wire vs. Stainless Steel Springs: Side-by-Side Comparison
The table below summarizes typical published properties. Tensile strength varies with wire diameter, with finer wire running toward the top of each range. For a fuller reference, see the spring material properties table at Engineers Edge.
| Property | Music wire (ASTM A228) | 302 stainless (ASTM A313) | 17-7 PH stainless |
| Minimum tensile strength (ksi) | 230 to 399 | 125 to 325 | 235 to 335 |
| Modulus of elasticity, E (Mpsi) | 30.0 | 28.0 | 29.5 |
| Modulus in torsion, G (Mpsi) | 11.5 to 12.0 | 10.0 | 11.0 |
| Max operating temperature | 250°F (121°C) | 550°F (288°C) | 650°F (343°C) |
| Corrosion resistance | Poor without a finish | Good | Good |
| Magnetic | Yes | Slightly, in spring temper | Yes |
| Relative cost | Lowest | Higher | Highest of the three |
Strength and Stiffness: The Hidden Cost of Switching
Engineers often swap music wire for 302 stainless late in a project, usually after a corrosion problem shows up in testing. This is where music wire vs stainless steel springs comparisons often go wrong: the two materials do not behave the same in the same geometry.
Spring rate is directly proportional to the modulus in torsion, G. Music wire has a G of about 11.5 to 12.0 million psi, while 302 stainless is about 10.0 million psi. As a result, a 302 spring wound to the exact same dimensions as a music wire spring will have a rate roughly 13 to 17 percent lower. In addition, 302 has a lower minimum tensile strength, so it cannot safely carry the same stress.
In practice, a straight material swap often means the spring no longer meets its load requirement, or it takes a set in service. The fix is usually a small redesign, such as a slightly larger wire, fewer active coils or a different free length. Catching this before the drawing is released is much cheaper than finding it during qualification. Our article on spring design for manufacturability covers how these decisions affect cost and lead time.
Corrosion Resistance and Finishing
If corrosion is the main concern, you have two paths: a stainless alloy, or music wire with a protective finish. Each comes with trade-offs.
- Plated music wire is usually cheaper, but plating can chip or wear, and it adds an outside processing step and lead time.
- Electroplating high-strength steel can cause hydrogen embrittlement, so plated music wire springs often need a baking step afterward. Skipping it risks sudden, brittle failures.
- Stainless steel needs no plating, but it is often passivated to remove surface iron and maximize corrosion resistance.
- For food, medical and washdown environments, stainless is usually the only practical choice, since plating flakes are not acceptable.
As a rule of thumb, if the spring will be exposed to moisture for most of its life, specify stainless. If exposure is occasional or the spring is enclosed, a finished music wire spring may be the better value.
Temperature Limits
Heat causes springs to relax, which means they gradually lose load. Music wire is generally limited to about 250°F. Type 302 and 316 stainless extend that to about 550°F, and 17-7 PH reaches about 650°F. Above that range, you are into specialty alloys such as Inconel.
Keep in mind that these are maximum figures. If a spring operates near its temperature limit at high stress, expect more relaxation. In that case, it is worth discussing the operating conditions with your spring manufacturer so they can recommend a lower working stress or a heat-setting process.
Magnetic Properties
Annealed 302 stainless is non-magnetic, but cold drawing it to spring temper makes it partly magnetic. If your application involves sensors, magnetic fields or medical imaging, do not assume 302 will be non-magnetic. Type 316 is less magnetic in spring temper, and non-ferrous alloys such as phosphor bronze or beryllium copper are the safest choice when magnetism must be minimized. Music wire and 17-7 PH are both magnetic.
Cost and Availability
On price, music wire vs stainless steel springs is not a close contest at the wire level. Music wire is the lowest-cost common spring material. Stainless steel wire costs more per pound, and 17-7 PH adds a heat-treatment step on top of that. Nickel and chromium prices also make stainless more exposed to raw material price swings, a trend we covered in our article on how critical minerals are reshaping the spring supply chain.
Still, wire is only part of the spring’s total cost. Plating, baking, inspection and lead time can close much of the gap between a finished music wire spring and a stainless one. For that reason, it pays to compare the finished part price, not the raw material price.
Quick Decision Checklist
Before you decide between music wire vs stainless steel springs, answer these questions:
- Will the spring be exposed to moisture, chemicals, salt, outdoor weather or washdown? If yes, start with stainless.
- Will it operate above 250°F? If yes, music wire is out. Consider 302, 316 or 17-7 PH.
- Is the space envelope tight, with a high load requirement? Music wire or 17-7 PH gives you the most strength per size.
- Is plating unacceptable because of contamination, appearance or embrittlement risk? Choose stainless.
- Does the part need to be non-magnetic? Avoid music wire and 17-7 PH, and confirm magnetic requirements for 302 before you commit.
- Is cost the main driver in a dry, enclosed application? Music wire is usually the best value.
- Are you switching an existing design from music wire to stainless? Recheck rate and stress before you release the change.
How to Specify Material on Your Drawing
Call out the alloy and the standard, such as “Music wire, ASTM A228” or “Stainless steel 302, ASTM A313,” along with any finish, passivation or heat-treatment requirements. If you are flexible, say so. A note such as “music wire or equivalent, subject to approval” lets your supplier suggest a better or cheaper option. For definitions of terms like spring index, set and stress relief, see our custom spring manufacturing glossary. And for a complete list of what to include in a quote request, read how to write a spring RFQ.
Work With a Manufacturer Who Runs Both
At Jackson Spring, we coil compression, extension and torsion springs and form wire parts from carbon steel, stainless steel, alloy steel and copper alloy wire. Our in-house stress relief ovens and grinding department let us handle post-coiling heat treatment and ground ends without sending parts out. If you are unsure which material fits your application, send us the operating conditions along with your drawing, and our engineers will recommend an alloy. Request a quote to get started.