17-4PH alloy - 1.4542 - ASTM F899


Alloy 1.4542 is a structurally hardened martensitic stainless steel which combines a hardness of about 48 HRC with good corrosion resistance.
This grade has a hardening peak at 480°C which allows easy ageing after machining on an initially solution treated condition. The grade is remelted to improve the cleanliness and homogeneity of the material.

Stainless has a number of sources in stock, as well as different formats or states of the product to suit your processing needs.

This product can also be custom made or cut into slugs by our service centres.

Main applications

Due to its good resistance to corrosion, its good hardness in the treated state (48HRC) and its resilience, the grade is used in particular in the manufacture of instruments for the medical sector (drills, etc.), in general mechanics, in the food industry and in the automotive sector.


The manufacturing processes associated with the transformation processes make it possible to obtain a homogeneous microstructure. In the treated state, the microstructure consists of martensite and nanometric intermetallic precipitates (Ni3Cu) which germinate during ageing.

17-4PH - 1.4542 - ASTM F899



The grade can be hot forged in the 900/1250°C temperature range. Resolving will be necessary to achieve maximum hardness.

The grade can be welded using most processes. Welding should preferably be done before ageing to avoid embrittlement of the heat affected zone.

Typical heat treatments

Corrosion resistance

The grade has very good corrosion resistance but must be passivated. The microstructure contains little or no chromium carbides, which makes it less susceptible to intergranular corrosion.

Standard Sizes

Round or flat bars annealed (Condition A or AT) or pre-treated. Surface ground or peeled depending on diameter
Flat bars made to measure in the annealed condition (consult us)
Other format : sheets

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

316L – 1.4404

304 – 1.4301


Martensitic stainless steels for tempering (type QT)

X15TN® – 1.4123


Martensitic steels with structural hardening (type PH)

17-4PH -1.4542

Custom® 455 – MX455 – 1.4543
Custom® 465 – 1.4614

Remelted austenitic stainless steels for prostheses and implants

M30NW® – 1.4472
316LVM – 1.4441