Name: 17-4PH
Brand: Ever Nickel
Price: 99.99 USD
Availability: InStock
Rating: 4.8 (50 reviews)

17-4PH

17-4 stainless is an age-hardening martensitic stainless combining high strength with the corrosion resistance of stainless steel. Hardening is achieved by a short-time, simple low-temperature treatment. Unlike conventional martensitic stainless steels, such as type 410, 17-4 is quite weldable. The strength, corrosion resistance and simplified fabrication can make 17-4 stainless a cost-effective replacement for high strength carbon steels as well as other stainless grades.

UNS: S17400

W. NR.: 1.4548

ASTM: A 564, A 693, A 705, TYPE 630

ASME: SA 564, SA 693, SA 705, TYPE 630

AMS: 5604, 5643, 5825

NACE: MR0175

ISO: 15156

Chemical Composition

The following table shows the chemical composition of grade 17-4 stainless steel.

Element	Content (%)
Iron, Fe	73
Chromium, Cr	15.0 - 17.5
Nickel, Ni	3.0 - 5.0
Copper, Cu	3.0 - 5.0
Manganese, Mn	1.0
Silicon, Si	1.0
Tantalum, Ta	0.45
Niobium, Nb (Columbium, Cb)	0.45
Nb + Ta	0.15 - 0.45
Carbon, C	0.070
Phosphorous, P	0.040
Sulfur, S	0.030

Physical Properties of Stainless Steel 17-4PH

Property	Imperial	Metric
Melting Range	2560-2625 °F	1404-1440 °C
Specific Heat	0.11 Btu/lb.-°F	460 Joules/gg-K
Specific Density	0.282 lb/in3	7.8 g/cm3
Electrical Resistivity	38.6 µΩ in	98 µΩ cm
Linear Coefficient of Thermal Expansion (70 °F to 200 °F) (21 °C to 93 °C)	6 [in/in/°F·106]	10.8 [μm/m·°C]
Linear Coefficient of Thermal Expansion (70 °F to 400 °F) (21 °C to 204 °C)	6 [in/in/°F·106]	10.8 [μm/m·°C]
Linear Coefficient of Thermal Expansion (70 °F to 600 °F) (27 °C to 316 °C)	6.2 [in/in/°F·106]	11.2 [μm/m·°C]
Linear Coefficient of Thermal Expansion (70 °F to 800 °F) (21 °C to 427 °C)	6.3 [in/in/°F·106]	11.2 [μm/m·°C]
Thermal Conductivity (@ 300 °F) (@ 149 °C)	124 Btu/(hr/ft²/in/°F)	17.9 [W/m-K]
Thermal Conductivity (@ 500 °F) (@ 260 °C)	135 Btu/(hr/ft²/in/°F)	19.5 [W/m-K]
Thermal Conductivity (@ 860 °F) (@ 460 °C)	156 Btu/(hr/ft²/in/°F)	22.5 [W/m-K]
Thermal Conductivity (@ 900 °F) (@ 482 °C)	157 Btu/(hr/ft²/in/°F)	22.6 [W/m-K]
Poisson’s Ratio (H900 Condition)	0.272	0.272
Modulus of Elasticity (H900 Condition)	28 x 106 ksi	197 x 103 MPa
Modulus of Rigidity in Torsion	9.68 x 103 ksi	67 x 103 MPa

Stainless Steel 17-4PH Mechanical Properties

Property	Imperial	Metric
Ultimate Tensile Strength	23,300 psi	160 MPa
Yield Strength (0.02%)	16,680 psi	115 MPa
Elongation (% in 2’’)	5%	5%
Rockwell Hardness C	35	35

Heat Treatment

Stainless Steel 17-4PH is available in the solution annealed condition at 1900 °F (1038 °C) and then air-cooled to 90 °F (32 °C).

However, additional heat treatments can produce various hardness and toughness levels. The most common treatments are listed in the table below.

Condition	Temperature [± 15 °F (± 8.4 °C)]	Cooling Method and Duration
H 900	900 °F (482 °C)	Air cooling for 1 hour
H 925	925 °F (496 °C)	Air cooling for 4 hours
H 1025	1025 °F (551 °C)	Air cooling for 4 hours
H 1075	1075 °F (580 °C)	Air cooling for 4 hours
H 1100	1100 °F (593 °C)	Air cooling for 4 hours
H 1150	1150 °F (621 °C)	Air cooling for 4 hours
H 1150 + 1150	1150 °F (621 °C) followed by 1150 °F (621 °C)	Air cooling for 4 hours followed by Air cooling for 4 hours
H 1150-M	1400 °F (760 °C) followed by 1150 °F (621 °C)	Air cooling for 2 hours followed by Air cooling for 4 hours

A brief history of 17-4PH

Originally developed during World War II, 17-4PH (also known as Type 630 stainless steel) was designed to address the need for high-strength materials with excellent corrosion resistance and ease of heat treatment. As one of the first precipitation-hardened stainless steels, it quickly gained popularity in the aerospace and military sectors for its ability to achieve superior mechanical properties through a simple heat treatment process. Over time, its versatility and reliability made it a preferred material across a wide range of industries.

Common applications

17-4PH is used in numerous industries requiring materials that combine strength, corrosion resistance, and durability. It is commonly employed in aerospace components such as turbine blades, fasteners, and structural parts. In the chemical and petrochemical industries, it is used in valves, pumps, and fittings exposed to corrosive environments. Additionally, 17-4PH finds applications in medical devices, nuclear power plants, and marine hardware due to its ability to maintain its properties in harsh conditions.

Resistance to corrosion and performance

With its high chromium and nickel content, 17-4PH provides excellent resistance to corrosion in most environments, including mildly acidic and chloride-containing atmospheres. The precipitation hardening process allows it to achieve high tensile and yield strengths while maintaining good toughness and ductility. Its performance remains consistent across a wide temperature range, from cryogenic conditions to elevated temperatures up to 600°F. Furthermore, the alloy exhibits strong resistance to stress corrosion cracking, making it reliable for critical applications.

Modern Innovations

Recent advancements in heat treatment and additive manufacturing have further expanded the potential of 17-4PH. Controlled processing techniques now allow for even greater consistency in mechanical properties, enabling its use in high-precision components. The alloy’s adaptability to advanced manufacturing technologies has made it a staple in modern aerospace, energy, and medical applications, where performance and reliability are paramount. Today, 17-4PH continues to be one of the most widely used and trusted stainless steels for high-performance applications.