Precipitation-Hardening (PH) Alloys – Exotic Metals
LLP
These alloys (the 600-series) gain exceptional strength
through a low-temperature "aging" heat treatment. They offer a unique combination of
high tensile strength and the corrosion resistance typically associated with the
300-series.
Precipitation Hardening Stainless Steel Grades
- 17-4PH (UNS S17400): The "workhorse" of PH steels. It provides an excellent
strength-to-weight ratio and is the standard for pump shafts, nuclear reactor
components, and aerospace fittings
- 15-5PH (UNS S15500): A refined version of 17-4PH. It uses vacuum remelting (VAR or
ESR) to create a more uniform microstructure, offering better transverse toughness
and ductility, especially in thicker sections
- 14-4PH: A specialized grade containing Molybdenum (2.0–2.5%), which provides
superior pitting resistance compared to 17-4PH, making it ideal for aggressive
chemical environments
Mechanical Properties (Condition H900)
| Grade |
Tensile Strength |
Yield Strength |
Hardness |
| 17-4PH |
≥ 1310 MPa |
≥ 1170 MPa |
40–45 HRC |
| 15-5PH |
≥ 1310 MPa |
≥ 1170 MPa |
40–45 HRC |
| 14-4PH |
≥ 1250 MPa |
≥ 1050 MPa |
38–42 HRC |
Martensitic Grades (400-Series)
These are "straight chromium" steels
($11.5\text{--}18\%\text{ Cr}$) that are heat-treated by quenching and tempering.
They are magnetic and designed for high hardness and wear resistance.
Martensitic Stainless Steel Grades
- 410: The basic martensitic grade. High strength and moderate corrosion resistance
- 420 / 420HC: High carbon variants. 420HC (High Carbon) is a premium upgrade used in
industrial knives and surgical tools for better edge retention and a peak hardness
of 56–59 HRC
- 422: Designed for service up to 650°C. It is the premier choice for steam turbine
blades and high-heat fasteners
Free-Machining & High-Toughness Stainless Steel Grades
- 416: The most machinable stainless steel (contains added Sulfur). Ideal for
high-speed automatic screw machine production of gears and valves
- 431: The most corrosion-resistant martensitic grade. It has high nickel content
(2%), giving it superior toughness for marine shafts and aircraft fasteners
- 430F: A free-machining version of the ferritic 430 grade, used for solenoid valves
and aircraft parts
The "Knife Steels" (440 Series)
- 440A / B: Balanced hardness and toughness for cutlery
- 440C: The "king" of hardness (58–62 HRC). Unmatched wear resistance for ball
bearings and valve seats
Specialized Turbine & Valve Grades (403 / 405)
Specialty Martensitic Grades
- 403: A high-quality "turbine quality" 410. It is processed to ensure a very clean
microstructure for high-stress cyclic loading in jet engines
- 405: A unique low-chromium grade (12%) with Aluminum added to prevent hardening
during cooling. This makes it ideal for applications involving welding, like furnace
partitions
Size & Product Inventory for Exotic Metals LLP
Exotic Metals LLP stocks and fabricates these grades in
the following formats:
Product Range
- Round Bars: 3mm to 500mm (Condition A, H900, H1025, H1150)
- Flat Products: Precision Strips, Shim Foils, and Plates up to 150mm
- Piping: Seamless high-pressure tubes for hydraulic systems
- Custom: Forged blocks, shafts, and CNC-machined components
Weight Reference: High-Strength Round Bar (Theoretical kg/m)
| Diameter |
Density 7.75 (400 Series) |
Density 7.80 (PH Series) |
| 10 mm |
0.61 |
0.61 |
| 25 mm |
3.80 |
3.83 |
| 50 mm |
15.22 |
15.32 |
| 100 mm |
60.87 |
61.26 |
