Which stainless steel for medical technology? Grades compared.
Corrosion, strength, purity — the three factors the material choice for medical fine wire depends on.
- Austenitic stainless steels dominate for medical fine wires — 304/304L (1.4301/1.4307), 316L (1.4404/1.4435) and the spring-hard 1.4310.
- Rule of thumb: 316L for high corrosion exposure and body contact, 304/304L as the proven standard, 1.4310 for spring applications.
- For the highest purity, grades are vacuum re-melted (e.g. 304V, 316LVM).
- The final choice is made per application — this guide provides the decision logic.
“Which material fits my medical application?” is the most common question before the first sampling. The answer hinges on three factors: corrosion resistance, mechanical requirement, and purity. This guide places the common stainless steel grades in context — as a basis for the conversation, not a substitute for it.
The common stainless steel grades at a glance.
| Material | AISI | Character | Typical application |
|---|---|---|---|
| 1.4301 / 1.4307 | 304 / 304L | Proven austenitic standard, good formability | Instruments, base components; 304V (vacuum) for higher purity |
| 1.4401 / 1.4404 | 316 / 316L | Molybdenum-alloyed, higher corrosion resistance | Body-contact/implant-related applications, catheter components |
| 1.4435 | 316L | 316L with higher Mo content, highly corrosion-resistant | Demanding medical applications |
| 1.4310 | 301/302 | Spring-hard, high tensile strength | Spring elements, dental technology/brackets |
The three decision factors.
Corrosion resistance
The closer to the body or the medium, the more likely molybdenum-containing 316L grades. 304/304L for less aggressive environments.
Mechanics
Spring, high-strength requirements lead to 1.4310. Forming and further processing favour 304/304L.
Purity
For the highest demands, vacuum re-melted variants (304V, 316LVM) — fewer inclusions, better surface, reproducible.
Why the process matters as much as the alloy.
Two wires of the same alloy are not the same. Multiple and vacuum re-melted grades have significantly fewer non-metallic inclusions — decisive for fatigue strength and surface quality at the finest diameters. This is exactly where the difference lies between “stainless steel wire” and “medical-grade fine wire”. We define the right grade together with you, application by application — from the first sample to series production.
Frequently asked questions.
Is 316L better than 304 for medical technology?
316L is more corrosion-resistant (molybdenum) and is preferred for body contact; 304/304L remain the proven standard for many applications.
What does “vacuum re-melted” mean?
A re-melting process that reduces inclusions and improves purity/surface — important for the finest medical wires.
What is 304V?
A vacuum re-melted version of 1.4301 (304) with increased purity.
Which grade for brackets/spring parts?
Often the spring-hard 1.4310, due to its high tensile strength.
Let's discuss your application.
We advise independently and find the right wire solution together with you.