Stainless Steel 17-4 PH Machining

Your guide to 17-4 PH Stainless Steel Machining



A precipitation hardening martensitic stainless steel

Can be supplied in an annealed or heat treated condition

Outstanding wear resistance and excellent hardness

17-4 PH is an American aerospace grade of stainless steel containing 4% copper. It has good machinability in the annealed condition but becomes more difficult after hardnening heat treatment.

This guide will take you through the main attributes, common applications, notes for designers and suitable finishing and treatments, as well as UK stock sizes and property tables. Don't forget to bookmark the page so you can refer back later.

If you are interested in 17-4 PH stainless machined parts, please scroll to the bottom of the page for more information about our service and to request a quote.

17-4 PH Guide: Properties, Applications and Design Considerations


What is 17-4 PH Stainless Steel?
17-4 PH is a precipitation hardening martensitic stainless steel. It is an American aerospace grade that contains 4% copper. It can be supplied in the annealed condition (condition A - although it should not be used in the annealed condition) or heat treated.

Heat treated conditions:

  • Condition H900 (900°F)
  • Condition H925 (925°F)
  • Condition H1025 (1025°F)
  • Condition H1075 (1075°F)
  • Condition H1100 (1100°F)
  • Condition H1150 (1150°F)

Stainless steel 17-4 PH has good machinability in the annealed condition - similar to that of stainless 304. Machining does become more difficult after hardening heat treatment.

Carbide or high speed steel tools should be used along with standard lubrication.

You may also see 17-4 PH referred to as:

  • 1.4542
  • UNS S17400
  • Grade 630
  • S17400
  • AISI 630
  • NACE MR 0175
  • ASTM A484
  • ASTM A564
  • AMS2303
  • AMS5643
  • AMS5643H1150
  • ASME SA564
  • X5CrNiCuNb16-4

Industry Examples: Aerospace | Defence | Chemical | Petrochemical | Food processing | Marine | Oil and gas


Typical Components & Applications: Fasteners | Valve parts | Spindles | Turbine blades | Undercarriage components | Missile and rocket fittings | Springs | Screws | Bolts | Gears | Bushes | Wear rings | Chemical process components

Main Attributes:
  • High tensile strength
  • High yield strength
  • Excellent hardness
  • Good corrosion resistance - on par with the more readily available stainless 304
  • Outstanding wear resistance
  • Good mechanical properties up to 316°C
  • Good welding characteristics
Can we meet your stainless steel 17-4 PH machining needs? Contact us now
Get a Quote

Further Reading & Resources

British Stainless Steel Association

CNC Machining Changing Supplier Guide

17-4 PH Machining Stainless Steel Machined Parts


Penta Precision provides the following 17-4 PH machining services:
  • CNC milling
  • CNC turning
  • Prototypes and batch runs
  • Insert installation
  • Part marking
  • Manual milling
  • Manual turning
  • Machining design advice
  • Design for manufacture service

Want to know more?


Find out how we can help you


Steel Machining


Stainless Steel Machining


Industry Sectors


Industry Sectors


Commitment To Quality


Commitment to Quality

Get A Quote