NITRONIC® 50 and 17-4 PH materials: features and benefits for the marine industry

NITRONIC® 50 e 17-4 PH
NITRONIC® 50 and 17-4 PH materials represent two strategic solutions for applications requiring mechanical strength, reliability and durability in aggressive environments such as those of themarine and defense industries. Both alloys are widely used for special bolts, fittings and components exposed to critical conditions, providing superior performance compared to traditional stainless steels such as AISI 316 or AISI 304.

Features of the NITRONIC® 50

The NITRONIC® 50, also known as XM-19, is an austenitic stainless steel with an exceptional balance of mechanical strength and corrosion resistance. It is particularly suitable for marine applications due to the following properties:

  • Superior corrosion resistance to AISI 316L, especially in chloride-rich environments
  • Tensile strength: about 690 MPa (in the HS version it can exceed even 900 MPa)
  • Excellent toughness even at low temperatures
  • Good weldability and workability

It is an optimal choice for screws, nuts and tie-rods intended for offshore platforms, ship installations and desalination systems.

Characteristics of 17-4 PH


Stainless steel 17-4 PH
(UNS S17400) is a precipitation-hardenable alloy characterized by high mechanical strength combined with good corrosion resistance. After hardening heat treatment, it achieves remarkable performance values:

Tensile strength: up to 1100 MPa depending on supply conditions:

Material Condition Treatment Cycle hardness reference standard
17-4PH (1.4542) H900 (standard) aging 482 °C x 1 h 40-47 HRC AMS5643
H925 aging 496 °C x 4 h 38-45 HRC
H1025 aging 552 °C x 4 h 34-42 HRC
H1075 aging 579 °C x 4 h 31-38 HRC
H1100 aging 593 °C x 4 h 30-37 HRC
H1150 aging 621 °C x 4 h 28-37 HRC
H1150 aging 620 °C x 4 h min 28 HRC ASTM A564
H1150M aging 760 °C x 2 h
+620 °C x 4 h
min 24 HRC
H1150D aging 620 °C x 4 h
+620 °C x 4 h
24-33 HRC
  • Excellent hardness and wear resistance
  • Good resistance in marine environments, although inferior to NITRONIC® 50 in terms of localized corrosion

Due to its versatility, 17-4 PH is widely used for structural bolts, shafts, pumps and fastening systems where high reliability is required.

Comparison of NITRONIC® 50 and 17-4 PH

To help in choosing the most suitable material, here is a summary comparison of NITRONIC® 50 and 17-4 PH:

Feature NITRONIC® 50 (XM-19) 17-4 PH (UNS S17400)
Microstructure Austenitic Hardenable by precipitation
Tensile Strength (Rm) ≈ 690 MPa Up to 1100 MPa
Corrosion resistance Excellent, superior to 316L Good, but less performant in salt water
Typical applications Offshore bolting, desalination, marine Structural bolts, pumps, shafts, fasteners

NITRONIC® 50 is preferred when corrosion resistance is a priority, while 17-4 PH is ideal for applications where high mechanical strength and hardness are needed.

Applications in the marine industry

Both NITRONIC® 50 and 17-4 PH are widely used in systems and structures in direct contact with seawater or saline environments:

  • Offshore platforms: bolts, nuts and tie rods resistant to chlorides and localized corrosion
  • Ships and naval installations: components subject to static and dynamic loads
  • Desalination systems: fittings and fixings for acid and salt-rich environments
  • Marine infrastructure: jetties, harbors, and structural support systems

The choice of material depends on the balance between mechanical requirements and the required level of corrosion resistance.

MF INOX Production

We at MF INOX produce special bolts in NITRONIC® 50 and 17-4 PH, guaranteeing quality and full certifications according to international standards. Due to the availability of raw material in stock, we are able to:

  • Offer fast delivery in 24/48 hours for urgent downtime
  • Making custom and non-standard components
  • Provide certifications EN 10204 3.1 and 3.2
  • Shipping worldwide with full traceability
If you need bolting in NITRONIC® 50 or 17-4 PH for applications in marine environments, contact us. MF INOX is your reliable partner for fast, certified solutions that withstand the most extreme conditions.
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