17-4 PH (S17400) is a precipitation-hardening stainless steel known for high strength, corrosion resistance, and excellent mechanical properties. It is widely used in aerospace, oil & gas, and engineering applications.
As a leading 17-4PH round bar supplier in UAE at Nifty Alloys LLC, with over a decade of experience sourcing from certified mills, we understand the technical requirements of buyers in the region. This guide provides a detailed overview of 17-4PH stainless steel, covering its properties, common applications, and how to source it effectively in the Middle East. We will explore its chemical composition, mechanical characteristics under various heat treatments, and its performance advantages over other stainless steel grades. Whether you are specifying materials for a new project or sourcing for maintenance, this article will equip you with the essential knowledge about this versatile alloy, available through our extensive stainless steel range
Feature | 17-4PH (in Condition H1150) | 304 Stainless Steel |
| Type | Martensitic, Precipitation-Hardening | Austenitic |
| Yield Strength | ~115 ksi (795 MPa) | ~30 ksi (205 MPa) |
| Corrosion Resistance | Good, comparable to 304 | Excellent |
| Magnetic? | Yes | No |
| Hardenable? | Yes, by heat treatment | No, by work hardening only |
17-4PH Round Bar chemical composition
TThe chemical composition of a 17-4PH round bar is precisely controlled to deliver its signature blend of strength and corrosion resistance. Its core elements are 15-17.5% chromium for corrosion protection and 3-5% nickel for toughness. However, the key to its precipitation-hardening capability lies in the addition of copper (3-5%) and niobium/columbium (0.15-0.45%).
During heat treatment, these elements form microscopic copper-rich precipitates within the steel's crystal structure. These precipitates obstruct internal dislocation movement, which significantly increases the material's strength and hardness. The niobium further refines the grain structure, enhancing toughness. This unique UNS S17400 chemical composition is what sets it apart from other stainless steels, enabling its high-performance characteristics. Each element plays a critical role in defining the alloy's final mechanical properties and its suitability for specific applications.
Element | Content (%) |
| Carbon (C) | ≤ 0.07 |
| Chromium (Cr) | 15.0 - 17.5 |
| Nickel (Ni) | 3.0 - 5.0 |
| Copper (Cu) | 3.0 - 5.0 |
| Manganese (Mn) | ≤ 1.00 |
| Silicon (Si) | ≤ 1.00 |
| Niobium (Nb) + Tantalum (Ta) | 0.15 - 0.45 |
| Iron (Fe) | Balance |
17-4 PH Material Equivalent
| Standard system | Designation |
|---|---|
| UNS | S17400 |
| AISI / SAE | 630 |
| EN / DIN | 1.4542 |
| EN name | X5CrNiCuNb16‑4 |
| JIS | SUS630 |
| Common name | 17‑4PH, Type 630 |



















































