Precipitation Hardening (PH) Stainless Steel

Centrifugally cast PH steel offers material properties that have lasting strength and corrosion resistance at a lower cost

Applications that require corrosion or oxidation resistance and need a metal material that holds its strength at elevated temperatures benefit from Precipitation Hardening (PH) steel.

A top-tier centrifugal casting foundry like Spuncast produces high-quality, easily repeatable PH steel products. And our PH steel tubes will meet the specs of the most demanding industries.

PH steel products have distinct advantages

PH steel contains chromium content at relatively high levels, which is what imparts remarkable resistance to corrosion and heat.

It is also a highly sought after metal because of its

  • High tensile strength
  • Increased hardness
  • Resistance to distortion
  • Oxidation resistance

Casting PH steel to match your specs and industry standards

Spuncast centrifugal cast PH steels equates to the following industry standards:

Industry Standards*
ASTM StandardA 747
AMS 5398
A 747
AMS 5348
Similar DIN1.4542
Spuncast AlloysCB7Cu-1CB7Cu-2
Similar Alloy17-4PH15-5PH
Chemical Specifications
Carbon max0.070.07
Manganese max0.70.7
Silicon max11
Phosphorus max0.0350.035
Sulfur max0.0350.03
Mechanical Properties
Tensile (min) - KSI (MPa)170(1170)145(1000)125(860)Heat treatments and physical
properties same as CB7Cu-1
Yield (min) - KSI (MPa)145(1000)
Elongation (2" min)
Brinell Hardness (10mm - 3000Kg -) Typical Values375 min277 min269 min
Density lbs/in0.28
Heat Treatment(H-900)(H1075)(H1150)

Spuncast Centrifugal Casting Matches Forged 17-4 PH Steel Specs But at a Lower Cost

We compared the performance of Spuncast PH steel material samples to the required specifications from a competitor’s forged 17-4 PH steel material.

The study showed in most cases, you can replace forged PH steel with centrifugally cast PH steel without any issues as long as the design is reconsidered to suit the process. The parts produced typically will be at a lower cost as well with the centrifugal casting process.

Competitor’s PH Steel Part Specification Requirements

Mechanical Property Requirements – UNS S17400, H1025, ASTM A564

UTS – 

1070MPa, 155ksi

Yield (0.2%) – 

1000MPa, 145ksi

Hardness – 

331 HB, 35 HRC

Elongation – 


Impact Prop. –

20 J / 15 ft.lbf (at 20 0F)

CB7Cu-1 Bar Properties Chart
Rockwell Hardness Evaluation

Spuncast’s PH Steel Part Specification Comparison

Using three PH steel sample castings from the Spuncast Foundry, our metallurgist documented the following results:

Charpy Impact Testing
Sample 8689
Sample 8652

The benefits of secondary processes to your PH steel

The quality of a PH steel cast product is further enhanced by using the appropriate secondary processes. It’s a material that can quickly develop high strength with simple heat treatments.

Heat Treating

Heat treating improves the PH steel’s strength, hardness, toughness, and corrosion resistance. Your metallurgist will select the most appropriate heat treatment for your material. Spuncast offers the following heat treatments:

  • Quenching and tempering to create better balance and stability.
  • Annealing for restoring ductility and allowing additional processing without cracking.
  • Normalizing to provide uniformity and a fine-grained structure.
  • Stress Relief to reduce the risk of unintended dimensional changes.

CNC Machining

Once cast, a PH steel product can be machined to quickly and selectively remove unneeded metal. CNC machining is a finishing process that works especially well with PH steel in a centrifugal casting environment because it:

  • Requires fewer steps to deliver far more complexity
  • Creates highly repeatable components accurately
  • Adds improved performance to the design
  • Eliminates unnecessary waste

Typical PH Steel Applications

The industries that request PH steel are looking for a material that offers a high degree of corrosion resistance. And they need a part that can hold up to extreme amounts of stress to meet the needs required for applications like:


Applications typically include:


Need to be lightweight with high strength and no distortions 

Valves, and other engine components

Endure speed and pressure differences which require high tensile strength

High strength shafts

Undergo extreme tension from both vehicle weight and weather 

Turbine blades

Demands a high degree of durability to withstand tremendous tensile stress

Spuncast PH Steel

Spuncast centrifugal casting processes have a long history of creating premium tubes using a wide variety of stainless steel. That includes 17-4 ph stainless steel equivalent ones that are known to offer accurate dimensions, and a smooth surface finish consistently.

Our team is skilled at producing custom PH steel castings for industries like oil & gas, water treatment, energy and power generation, food processing, and defense.


A: PH stands for Precipitation Hardening (PH), a heat treatment used to increase the yield strength and produce excellent high-temperature strength in super alloys.

A: A forged 17-4 PH stainless steel has an average hardness of 352 HB. The cast equivalent of 17-4 PH stainless steel yields a hardness of  331 HB, 35 HRC.

A: It’s a material containing chromium content at relatively high levels, which means it has a remarkable resistance to corrosion and heat.

Secondary heat treatments further improve the PH steel’s strength, hardness, toughness, and corrosion resistance.

Take the Spuncast Challenge

We’re up to the challenge of meeting your specs and beating the competition on overall costs.

Send us the specs and application needs on your next project requiring PH steel. We’ll provide a quote and full metallurgical makeup to show how we can produce a stronger, more cost-effective tube for your part.

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