Material Comparison
304 vs 316 stainless wire: which grade do you need?
Both grades look identical and both resist rust — but one handles saltwater and chemicals far better. Here's how to choose, by application.
Quick answer:If you're near salt water, chemicals, or need food-grade approval — choose 316. For everything else, 304 gives you the same corrosion resistance at lower cost.
Grade comparison at a glance
304 Stainless
- Composition
- 18% chromium, 8% nickel. No molybdenum.
- Corrosion resistance
- Excellent general-purpose resistance. Handles humidity, mild chemicals, and atmospheric exposure well.
- Chloride resistance
- Moderate. Can pit over time in chloride-rich environments (salt spray, seawater).
- Cost
- Lower. The more economical choice for most jobs.
- Typical applications
- Industrial, construction, insulation work, interior bundling, general aerospace MRO.
- Standard
- ASTM A580
- AWW availability
- Standard stock for tie wire and lockwire
316 Stainless
- Composition
- 18% chromium, 10% nickel, 2–3% molybdenum — the key addition.
- Corrosion resistance
- Superior in aggressive environments. The molybdenum resists pitting from chlorides, acids, and oxidizing agents.
- Chloride resistance
- Excellent. The marine grade. Designed for saltwater, coastal air, and chemical processing environments.
- Cost
- Higher. Premium is worth it where 304 would corrode.
- Typical applications
- Marine, coastal, chemical processing, food and pharmaceutical, severe MRO environments.
- Standard
- ASTM A580
- AWW availability
- Standard for stainless aircraft cable; tie wire and lockwire available on request
Choose 304 when…
- ›The application is indoors or in a sheltered environment
- ›You need general-purpose corrosion resistance for construction or insulation work
- ›The spec calls for 302/304 stainless (most aerospace tie wire and lockwire)
- ›Cost is a factor and chloride exposure is not
- ›You need immediate off-the-shelf availability
Choose 316 when…
- ›The wire will be exposed to saltwater, sea spray, or coastal air
- ›The environment involves chloride-bearing chemicals or acidic conditions
- ›The application is food processing, pharmaceutical, or requires food-grade certification
- ›The spec or customer explicitly calls out 316 (severe marine/chemical MRO)
- ›Long service life in a harsh environment justifies the added cost
How this applies by product
Stainless steel tie wire
American Wire Works stocks 304 stainless tie wire as standard — the right choice for the vast majority of construction, insulation, and industrial bundling work. If your project is in a marine, coastal, or chemical environment and you need 316, contact us for a quote; we can source it on request.
View stainless steel tie wire →Stainless lockwire (safety wire)
MS20995C covers 302, 304, and 316 stainless lockwire. In practice, most aerospace buyers accept 302/304, which is what AWW stocks and what most MRO programs use. 316 lockwire is available on request and is typically specified only for applications in severe marine or chemical processing environments where chloride pitting is a documented concern.
View stainless steel lockwire →Stainless aircraft cable
For stainless aircraft cable, AWW stocks 316 marine-grade stainless as standard. This reflects where stainless cable is most commonly specified: rigging, marine, and outdoor structural applications where the superior chloride resistance of 316 is worth the premium. If your application calls specifically for 304, reach out — we can discuss options based on your spec and quantities.
View stainless aircraft cable →Frequently asked questions
What is the difference between 304 and 316 stainless steel wire?
The key difference is molybdenum. 316 stainless contains 2–3% molybdenum in addition to 18% chromium and 10% nickel, which gives it superior resistance to chlorides, saltwater, and acidic environments. 304 stainless has 18% chromium and 8% nickel but no molybdenum — it offers excellent general-purpose corrosion resistance at a lower cost.
When should I use 316 stainless wire instead of 304?
Choose 316 when your application involves exposure to saltwater or coastal air, chlorides, acidic chemicals, or when food-grade or pharmaceutical standards require it. 316 is the marine grade for good reason — the molybdenum prevents the pitting corrosion that can occur with 304 in chloride-rich environments.
Is 304 or 316 stainless wire better for tie wire?
For most tie wire applications — construction, insulation, bundling — 304 stainless is the right choice and what American Wire Works stocks as standard. 304 provides excellent corrosion resistance at lower cost. 316 stainless tie wire is available on request for marine, coastal, or chemical environments where chloride exposure is a concern.
Which stainless grade is used for lockwire (safety wire)?
MS20995C covers 302, 304, and 316 stainless lockwire. In practice, most aerospace MRO buyers accept 302/304, which meets the spec and is more widely available. 316 lockwire is typically specified for severe marine or chemical MRO environments where chloride exposure is a real concern.
Does American Wire Works stock 316 stainless wire?
Yes. American Wire Works stocks 316 marine-grade stainless for aircraft cable as standard. For tie wire, 304 is our standard stock and 316 is available on request. For lockwire, contact us to confirm current availability for your required diameter and spec.
Not sure which grade fits your job?
American Wire Works has supplied stainless wire since 1940. Tell us your application and environment — we'll point you to the right grade and get you a quote fast.