Stainless Steel — High-Performance Grades for Medical, Aerospace & Industrial Applications
STAINLESS stocks a comprehensive range of high-performance stainless steel grades to meet the most stringent requirements of medical, aerospace, microtechnology and industrial markets.
Stainless supplies stainless steel produced with or without remelting, hot rolled, forged or cold processed to achieve specific surface finishes and thermal states. Our stainless steel grades are primarily used in the medical device and surgical instrumentation sector and the aerospace and aeronautical industries, but also for microtechnology and the industrial market. Available formats include bars, wires, flat bars, forged blocks, strips and tubes, in a wide range of dimensions and tolerances. Stainless steels offer outstanding corrosion resistance and, for certain grades, high-temperature resistance, these heat-resistant grades are commonly referred to as refractory stainless steels.
What is stainless steel?
Stainless steel is an iron-based metallic alloy in which chromium is the key alloying element, providing corrosion resistance through the formation of a thin, self-repairing passive oxide layer on the metal surface. A minimum chromium content of approximately 10.5% is required to classify a steel as stainless. The addition of other elements — nickel, molybdenum, copper or nitrogen — further enhances corrosion resistance, mechanical strength and formability depending on the application.
Corrosion in stainless steel can be uniform or localised (known as pitting corrosion or crevice corrosion), and the grade selection directly determines resistance to these failure modes.
Depending on their microstructure and mechanical properties, stainless steels are classified into four main families:
- Austenitic stainless steels — the most widely used family, offering excellent corrosion resistance and weldability
- Martensitic stainless steels — hardened by heat treatment, offering high mechanical strength
- Ferritic stainless steels — magnetic, good corrosion resistance, lower cost
- Duplex stainless steels — combining austenitic and ferritic properties for superior strength and stress corrosion resistance
The medical, industrial and aeronautical sectors all use these steels.
Austenitic steel
Austenitic steels are especially used for medical sector instrumentation and some remelted steels are used by the prosthesis and implant markets due to their high corrosion and fatigue resistance. Austenitic steels can only be hardened by work hardening.
Martensitic steel
Martensitic, quenched and tempered medical steels are reserved for instrumentation requiring higher mechanical strength than austenitic steels. They are hardened by quenching followed by tempering, in which case they are known as QT (Quenching and Tempering) steels, or by quenching followed by ageing, in which case they are known as martensitic steels with PH (Precipitation Hardening) type structural hardening. The latter harden during ageing, whereas QT type steels have a hardening peak after quenching and are softened during tempering.
Stainless has a wide range of stainless steels from the world's leading producers.
Available formats: Strips, tubes, bars, wires, flat bars, forged blocks, powders
Other formats are available from stock or on order. Contact us.
Austenitic stainless steels
316 – 1.4401
304L- 1.4307
1.4435
A286 – 1.4980
Nitronic®50 – 1.3964
Nitronic®60
Martensitic steels with structural hardening (type PH)
17-7PH – 1.4568
Remelted austenitic stainless steels for prostheses and implants
M30NW® – 1.4472
316LVM – 1.4441
Biodur® 108
Frequently Asked Questions, Stainless Steel
What is stainless steel made of?
Stainless steel is an iron-based alloy containing a minimum of 10.5% chromium, which forms a thin, self-repairing passive oxide layer that protects the metal from corrosion. Additional elements such as nickel, molybdenum, copper and nitrogen are added to enhance corrosion resistance, mechanical strength and weldability depending on the intended application.
What are the main grades of stainless steel?
The most commonly used stainless steel grades are:
- 316L (1.4404) — austenitic grade with added molybdenum for superior corrosion resistance; widely used in medical devices and marine environments
- 304 (1.4301) — the most widely used austenitic grade; excellent general corrosion resistance and weldability
- 17-4PH (1.4542) — martensitic precipitation-hardening grade offering high mechanical strength; used in aerospace and surgical instrumentation
- 316LVM (1.4441) — vacuum remelted grade for implantable medical devices (prostheses, implants)
- 1.4125 (440C) — high-carbon martensitic grade with excellent hardness; used for cutting instruments and bearings
STAINLESS stocks all these grades in bars, strips, wires and forged blocks, with full traceability and mill certifications.
What is the difference between austenitic and martensitic stainless steel?
Austenitic stainless steels (such as 304 and 316L) are non-magnetic, cannot be hardened by heat treatment, and offer excellent corrosion resistance and weldability. They are the most widely used family, particularly suited to medical instrumentation, food processing and chemical environments.
Martensitic stainless steels (such as 1.4021 and 17-4PH) can be hardened by quenching and tempering or by precipitation hardening, achieving significantly higher mechanical strength. They are preferred for applications requiring cutting edges, high fatigue resistance or elevated loads — surgical instruments, aerospace fasteners, bearings and high-stress components.
What stainless steel grades are used in medical devices?
Medical-grade stainless steels must comply with standards such as ASTM F899, ASTM F138 and ISO 5832-1. The most commonly used grades include:
- 316L / 316LVM (1.4441) — for implants and prostheses requiring biocompatibility and vacuum remelting
- M30NW (1.4472) — remelted austenitic grade for high-fatigue implant applications
- 17-4PH (1.4542) — for surgical instruments requiring high strength and corrosion resistance
- 1.4125 (440C) — for cutting instruments, blades and needle tips
STAINLESS supplies medical-grade steels with full documentation, certificates of conformity and traceability to the melt.
What stainless steel grades are used in aerospace?
Aerospace applications require stainless steels that combine high mechanical strength, fatigue resistance and corrosion resistance, often certified to AMS or NADCAP standards. Key grades include:
- 17-4PH (1.4542, AMS 5643) — for structural fasteners, shafts and fittings
- A286 (1.4980) — austenitic superalloy for high-temperature applications up to 700°C
- Custom 465 (1.4614) — ultra-high strength martensitic grade for landing gear and actuation systems
- Nitronic 50 (1.3964) — high-strength austenitic grade for seawater and cryogenic applications
What formats and dimensions does STAINLESS supply?
STAINLESS supplies stainless steel in the following forms:
- Bars (round, flat, hexagonal) — from small diameters to large sections
- Strips and foils — including very thin gauges down to a few microns for microtechnology
- Wires — including fine wire and shaped profiles
- Forged blocks — for high-integrity applications
- Tubes — for medical and industrial use
- Powders — for additive manufacturing (medical, aerospace)
Custom cutting, chamfering, grinding and surface treatment services are available on request.
What is the difference between 316L and 316LVM stainless steel?
Both are low-carbon austenitic grades with molybdenum (type 1.4404 / 1.4441), but 316LVM is produced by vacuum induction melting followed by vacuum arc remelting (VIM-VAR). This double remelting process significantly reduces non-metallic inclusions and improves fatigue strength, making 316LVM the preferred grade for implantable medical devices such as hip and knee prostheses, bone screws and cardiovascular components. 316L is used for surgical instruments and industrial applications where implantability is not required.