ThePipingMart Blog Grades 17-4 PH Stainless Steel (UNS S17400) – Composition, Properties, and Uses

17-4 PH Stainless Steel (UNS S17400) – Composition, Properties, and Uses

17 4 ph Stainless Steel

If you are looking for durable, strong, and corrosion-resistant stainless steel, then stainless steel grade 17-4 PH is your best option. This type of stainless steel is used in various applications due to its strength and versatility. This blog post will discuss the properties and uses of this grade of stainless steel.

Stainless Steel Grade 17-4 PH is a precipitation-hardening martensitic stainless steel that offers high strength, hardness, superior corrosion resistance, formability, and better weldability than other grades of stainless steel. It can be heat treated to achieve a wide range of hardness levels from 40 to 65 HRC. It has an excellent combination of mechanical properties, including good strength, toughness, and fatigue resistance at temperatures up to 600F (316C).

The most common uses for this grade of stainless steel include aerospace components such as landing gear components; automotive parts such as valve springs; medical implants; food processing equipment; oil and gas industry components; and chemical processing equipment. This type of stainless steel is also often used in construction due to its durability, strength, and easy maintenance.

It has excellent corrosion resistance in fresh and saltwater environments making it ideal for marine applications such as boat fittings or dock hardware. 17-4 PH is also used to manufacture surgical instruments due to its ability to resist corrosion caused by exposure to body fluids. Its excellent machinability makes it ideal for producing precision parts with tight tolerances, such as gears or valves.

What Forms is 17-4 PH Stainless Steel Available at Piping Mart?

  • 17-4 PH Stainless Steel Pipes
  • 17-4 PH Stainless Steel Screw
  • 17-4 PH Stainless Steel Tubing
  • 17-4 PH Stainless Steel Sheet
  • 17-4 PH Stainless Steel Plates
  • 17-4 PH Stainless Steel Bars

17-4 PH Stainless Steel Chemical Composition

The chemical composition of 17-4 stainless steel are:

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

17-4 PH Stainless Steel Properties

17-4 SS is a martensitic, chromium-nickel-copper precipitation-hardening stainless steel. Its main properties are high strength, good corrosion resistance, and good mechanical properties at high temperatures. It is widely used in the aerospace, chemical, and petrochemical industries.

17-4 PH Stainless Steel Physical Properties

The physical properties of 17-4 stainless steel are:

Properties Metric Imperial
Density 7.75 g/cm3 0.280 lb/in³

17-4 PH Stainless Steel Mechanical Properties

The mechanical properties of 17-4 stainless steel are:

Properties Metric Imperial
Shear modulus 77.4 GPa 11200 ksi
Elastic modulus 190-210 GPa 27557-30458 ksi
Poisson’s ratio 0.27-0.30 0.27-0.30
Hardness, Brinell 352 352
Hardness, Knoop (estimated from Rockwell C) 363 363
Hardness, Rockwell C 36 36
Hardness, Vickers (estimated from Rockwell C) 349 349

17-4 PH Stainless Steel Thermal Properties

Properties Metric Imperial
Thermal expansion co-efficient (@ 21-93°C/69.8-199°F) 10.8 µm/m°C 6.00 µin/in°F
Thermal conductivity ( for condition H 900 at 149ºC. 22.6 W/mK for H 900 at 482ºC) 17.9 W/mK 124 BTU in/hr.ft².°F

17-4 PH Stainless Steel Equivalent

Other designations that are equivalent to grade 17-4 stainless steel are listed in the following table.

AISI 630 ASTM A693 (630) AMS 5342 MIL-S-81506
AMS 5604 ASTM A705 (630) AMS 5343 SAE J467 (17-4PH)
AMS 5622 MIL C-24111 AMS 5344 ASME SA705
AMS 5643 MIL P-47183 AMS 5355 ASME SA564
ASTM A564 (630) MIL S-81591 AMS 5825

17-4 PH Stainless Steel Specifications

AMS 5643 (Bar)
AMS 2303 (Bar)
ASTM A484 (Bar)
ASTM A564 (Bar)
Project 70™ (Bar)
Custom 630™ (Bar)
AMS 5604 (Sheet & Plate)
ASTM A693 (Sheet & Plate)
UNS S17400

17-4 PH Stainless Steel Uses

UNS S17400 is incredibly versatile, with various services across sectors like automotive engineering, aerospace, firearms manufacturing, and energy production. This corrosion-resistant alloy is noted for its excellent strength, hardness, and high fatigue strength once it has been heat treated. It can be used to create components like jet turbine blades and aircraft fixtures, thanks to its strength and resistance to stress corrosion cracking. This same property makes it ideal for use in nuclear plants where safety-critical components are needed that won’t corrode quickly over time. Furthermore, the high hardness level allows 17-4 PH stainless steel to manufacture tools such as saw blades and ball bearings that require high wear resistance. The ability of this alloy to maintain form when exposed to large temperature changes also makes it suitable for chemical engineering work such as refining processes.


In conclusion, SS grade 17-4 PH is an incredibly versatile material with many beneficial properties and applications. Its high strength and exceptional corrosion resistance make it ideal for many industries, including aerospace, automotive, medical, food processing, oil & gas, chemical processing, and construction. Its machinability makes it suitable for precision parts with tight tolerances, while its excellent weldability ensures secure connections between pieces when fabrication or repair work is needed. For these reasons and more, it is no surprise that this type of stainless steel remains one of the most popular materials today.

Related Post