17-7PH Stainless Steel Alloy

UNS: S17700
EN-DIN: 1.4568

17-7PH Stainless Steel Strip, Coil & Sheet

  • AMS 5528
  • AMS 5529
  • MIL-S-25043
  • ASTM A693 (Listed as Grade 631-UNS S17700)

Our wide capabilities give us a unique ability to supply all of your 17-7PH stainless steel strip, coil, and sheet needs.

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17-7PH Stainless Steel Alloy Description:

17-7 PH stainless steel alloy is a precipitation-hardening stainless steel that provides high strength and hardness, excellent fatigue properties, good corrosion resistance, good formability, and minimum distortion upon heat treatment. The alloy provides valuable property combinations particularly well suited for aerospace applications. This special alloy also provides benefits for other applications requiring high strength and good corrosion resistance, as well as excellent properties for flat springs at temperatures up to 600°F (316°C).

Heat Treatments

17-7PH Stainless Standard Heat Treatments:

This material requires three essential steps in heat treating:

  • Austenite conditioning.
  • Cooling to transform the austenite to martensite.
  • Precipitation hardening to Condition TH 1050 or RH 950.

To obtain the highest mechanical properties from the alloy, Condition A material is transformed to martensite at the mill by cold reduction to Condition C. Hardening to Condition CH 900 is accomplished with a single, low-temperature heat treatment.

Nominal Composition


Physical Properties

Condition ACondition THCondition RH 950
Density – lbs/in³ (g/cm³)0.282 (7.81)0.276 (7.65)0.276 (7.65)
Modulus of Elasticity (E) – ksi (Gpa)29.0 x 10³ (200)29.0 x 10³ (200)
Electrical Resistivity – microhm-cm808283
Magnetic Permeability – @ 50 oersteds1.4 – 3.6120 – 167113 – 130
Magnetic Permeability – @ 200 oersteds (Maximum)1.4 – 3.2 (1.4 – 3.6)46 – 55 (134 – 208)44 – 52 (119 – 135)
Thermal Conductivity* 300°F (149°C) – BTU/hr/ft.²/in/hr/°F  (W/m•K) 117 (16.87)117 (est) (16.87)
Thermal Conductivity* 500°F (260°C) – BTU/hr/ft.²/in/hr/°F  (W/m•K) 128 (18.46)128 (est) (18.46)
Thermal Conductivity* 900°F (482°C) – BTU/hr/ft.²/in/hr/°F  (W/m•K) 146 (21.05)146 (est) (21.05)
Coefficient of Expansion* 70 – 200°F (21 – 193°C)8.5 x 10⁻⁶ (15.3)5.6 x 10⁻⁶ (10.1)5.7 x 10⁻⁶ (10.3) 
Coefficient of Expansion* 70 – 400°F (21 – 204°C)9.0 x 10⁻⁶ (16.2)6.1 x 10⁻⁶ (11.0)6.6 x 10⁻⁶ (11.9)
Coefficient of Expansion* 70 – 800°F (21 – 427°C)9.6 x 10⁻⁶ (16.0)6.6 x 10⁻⁶ (11.9)6.9 x 10⁻⁶ (12.4)
Typical Room Temperature Mechanical Properties

Typical Mechanical Properties

Typical mechanical properties are based on AK source on ASTM A693.

ConditionTensile Strength (UTS)* ksi (MPa)0.2% YS* ksi (MPa)Elongation% in 2” (50.8 mm)Hardness Rockwell
A130 ksi (896 MPa)40 ksi (276 MPa)35%85 HRBW
TH 1050200 ksi (1379 MPa)185 ksi (1276 MPa)9%43 HRCW
RH 950235 ksi (1620 MPa)220 ksi (1517 MPa)6%48 HRCW
C220 ksi (1517 MPa)190 ksi (1310 MPa)5%43 HRCW
CH 900265 ksi (1827 MPa)260 ksi (1793 MPa)2%49 HRCW

Corrosion Resistance:

Corrosion resistance in Conditions TH 1050 and RH 950 is generally superior to that of the standard hardenable chromium types of stainless steels such as Types 410, 420 and 431, but is not quite as good as chromium-nickel Type 304. Corrosion resistance in Condition CH 900 approaches that of Type 304 in most environments.


In Condition A, the alloy can be formed comparably to Type 301. It work-hardens rapidly and may require intermediate annealing in deep drawing or in forming intricate parts. Springback is similar to that of Type 301. This alloy is extremely hard and strong in Condition C. Therefore, fabrication techniques for such materials must be used.


The precipitation hardening class of stainless steels is generally considered to be weldable by the common fusion and resistance techniques. Special consideration is required to achieve optimum mechanical properties by considering the best heat-treated conditions in which to weld and which heat treatments should follow welding. This particular alloy is generally considered to have poorer weldability compared to the most common alloy of this stainless class, 17-4PH Stainless Steel. A major difference is the high Al content of this alloy, which degrades penetration and enhances weld slag formation during arc welding. Also, the austenite conditioning and precipitation hardening heat treatments are both required after welding to achieve high strength levels. When a weld filler is needed, W 17-7 PH is most often specified.

Limitation of Liability and Disclaimer of Warranty:
  • The content in these data sheets is provided primarily by third-party melting mills and is provided for reference only. It is not intended for engineering or design.
  • Applications may be discussed, however, Combined Metals Company, LLC, does not recommend or endorse any material for any particular end use or application.
  • The data included in this data sheet are typical values and may vary.
  • Combined Metals Company, LLC, makes no representations or warranties, express or implied, as to the accuracy, completeness, condition, suitability, performance, fitness for a particular purpose, or merchantability of any information contained in any data sheet.

In no event will Combined Metals Company, LLC, be liable for any damages whatsoever arising from the use of the information included in the data sheets.

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