Stainless Steel 17-4 H900 hardness (HRC)
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Are you looking for precise hardness data and real-world performance insights for Stainless Steel 17-4 H900?For engineers and buyers, hardness is often the key parameter when selecting materials for high-load, wear-resistant, or precision components.
This guide provides a clear, data-driven explanation of 17-4PH stainless steel in the H900 condition, focusing on HRC hardness, mechanical performance, applications, and advantages.
What Is 17-4PH H900?
17-4PH (UNS S17400 / EN 1.4542) is a precipitation-hardening martensitic stainless steel.The H900 condition refers to solution treatment followed by aging at approximately 900°F (≈482°C), which maximizes hardness and strength through fine copper-rich precipitates.This condition is widely used where high hardness, high strength, and dimensional stability are required.
What is the hardness of 17-4PH stainless steel H900 in HRC?
The typical hardness range is 40–44 HRC, depending on section size and heat treatment accuracy.
| Condition | Hardness (HRC) |
|---|---|
| 17-4PH H900 | 40 – 44 HRC |
| 17-4PH H1025 | 35 – 38 HRC |
| 17-4PH H1150 | 28 – 32 HRC |
17-4PH stainless steel Chemical Composition (Typical)
| Element | Content (%) |
|---|---|
| Chromium (Cr) | 15.0 – 17.5 |
| Nickel (Ni) | 3.0 – 5.0 |
| Copper (Cu) | 3.0 – 5.0 |
| Niobium + Tantalum (Nb + Ta) | 0.15 – 0.45 |
| Carbon (C) | ≤ 0.07 |
| Iron (Fe) | Balance |
Mechanical Properties of 17-4PH H900
| Property | Typical Value |
|---|---|
| Tensile Strength | ~1310 MPa |
| Yield Strength (0.2%) | ~1170 MPa |
| Hardness | 40 – 44 HRC |
| Elongation | ~10 – 12% |
| Density | ~7.75 g/cm³ |
17-4PH H900 machinability
17-4PH in the peak-aged H900 condition (38 HRC, tensile strength ≥ 1310 MPa) has poor machinability compared to annealed austenitic grades like 304-requiring cutting speeds reduced by ~30–40 %, rigid tooling (carbide inserts), and frequent tool changes to manage work hardening and tool wear.
17-4PH H900 corrosion cracking
While 17-4PH H900 offers good general corrosion resistance (PREN ≈ 24–30), its high strength and hardness make it more susceptible to chloride-induced stress corrosion cracking (SCC) than softer stainless steels like 304 or 316, particularly in environments with > 50 ppm Cl⁻ and tensile stresses above 50 % of yield strength.
Is 17-4 H900 harder than H1025?
Yes. H900 is the hardest standard aging condition for 17-4PH.
Is 17-4 H900 suitable for wear-resistant parts?
Yes. Its high hardness and strength make it suitable for moderate wear and high-load components.
Can 17-4PH H900 be machined?
Yes, but machining is usually done before aging to avoid excessive tool wear.
17-4PH H900 Applications
17-4PH H900 is widely selected for components requiring high surface hardness and structural strength:
✔ Aerospace brackets and fittings
✔ High-strength shafts and pins
✔ Valve components and pump parts
✔ Precision mechanical fasteners
✔ Oil & gas and energy industry components
In many cases, H900 replaces alloy steels to reduce weight while maintaining hardness.
H900 vs Surface Hardened Steels
| Aspect | 17-4PH H900 | Carburized Alloy Steel |
|---|---|---|
| Hardness depth | Through-hardness | Surface only |
| Corrosion resistance | Good | Poor |
| Heat treatment control | Simple aging | Multi-step |
| Dimensional stability | High | Moderate |
For many precision parts, through-hardness at 40–44 HRC is a significant design advantage.
17-4 H900 suppliers
GNEE offers 17-4PH H900 (EN 1.4542 / UNS S17400) in various product forms, including cold-rolled/hot-rolled steel plates with thicknesses of 0.3–6.0 mm, round bars with diameters of 3–350 mm, square bars with side lengths of 10–200 mm, steel strips with widths ≤ 1500 mm, and custom-formed parts.
All products comply with ASTM A693 and EN 10088-2 standards and are delivered in the H900 peak aging condition (hardness ~38 HRC, tensile strength ≥ 1310 MPa, yield strength ≥ 1170 MPa).
Packaging: Triple protection with moisture-proof paper + plastic film + wooden pallet/wooden crate ensures no rust or mechanical damage during transportation; large-sized plates are additionally reinforced with steel straps.
Shipping: Global sea freight (container/bulk carrier) is supported, with a typical delivery time of 7–15 days for regular orders.
Certificates: Each batch of goods comes with an EN 10204 3.1 factory test certificate (including chemical composition, mechanical properties, and heat treatment process records), and SGS/BV/TÜV third-party inspection reports can be provided upon request to meet the traceability requirements of high-demand industries such as nuclear power, aerospace, and medical.
