Stainless Steel 17-7PH®

General Description

17-7 PH® is a precipitation hardened (PH) stainless steel. It has the same easy-to-work characteristics of the 300 series alloys, yet it is capable of being hardened by a simple heat treatment. It has higher tensile strength/hardness compared to the 300 series when cold worked, and much higher tensile strength/hardness when heat treated. For miniature tubing, it’s typically sold in Condition “C” (cold worked) or “CH900”, (cold worked and then heat treated to 900F). Other conditions and heat treatments are available based on the desired properties.

*17-7 PH® is a registered trademark of AK Steel Corporation.


  • Biopsy needles
  • Cutting tools
  • Catheters
  • Punch tools
  • Increased stiffness needles

Reference Standards

  • AMS 5568
  • ASTM A693
  • ASTM F899


  • Cold working will achieve higher tensile strengths as well as leaving the material slightly magnetic.
  • Heat treating will result in additional strength and hardness—perfect for applications requiring high wear-resistance and/or stiffness.
  • Ability to form at low yield strength and high elongations followed by a strengthening heat treat.
  • Good general corrosion resistance

Typical Chemistry

Carbon 0.09%
Manganese 1.00%
Phosphorous 0.04%
Sulfur 0.03%
Silicon 1.00%
Chromium 16.00% 18.00%
Nickel 6.50% 7.75%
Aluminum 0.75% 1.50%

Possible Mechanical Properties

Hardness 25 HRC 44 HRC 50 HRC
Tensile Strength 140 ksi 200 ksi 260 ksi
Elongation 35% 5% 2%
Tensile Strength

General Properties

Density (annealed) 0.289 lb/in3
Elastic modulus 29,000 ksi
Shear modulus 11,200 ksi
Mean specific heat (0-100C) 0.120 Btu/lb/F
Mean CTE (70-200F) 8.5 x10-6 in/in/F
Electrical resistivity 80 micorohm-cm
Magnetic Permeability (Annealed) 1.4 – 3.6

Tubing-specific Requirements

  • Lengths: Tubing is normally furnished in mill lengths of 5 ft, but it can be supplied in up to 20 ft lengths with a shear cut end.
  • Cut End Finish: Precision cut-to-length pieces with burr-free ends can be furnished when specified.
  • Roundness: Difference in minimum and maximum OD measurements must be equal or less than half the OD tolerance.
  • Surface Finish: OD and ID surface finish (Rq or RMS) limits may be specified. ID and OD surface finish values are only reported for dimensions >0.020".
  • Typical OD Surface: < 20 μin Rq.
  • ID Surface finish: Depends on the reduction (drawing) method. Free sunk tubing has a typical ID surface finish <150 μin Rq. Plug drawn tubing can have an ID surface finish range with values as low as < 20 μin Rq.
  • Straightness: No deflection greater than 5% of the outside diameter for tubing with OD ≥ 0.020” or 0.001” maximum deflection for tubing with OD <0.020”. Any special straightness requirements shall be agreed upon between the purchaser and supplier. Tubing should not “wobble” as defined per ASTM F2819,

Additional tubing specification information can be found in K001-15a Standard Specification for Miniature Laser Welded and Drawn Stainless Steel and Nickel-Chromium Alloy Tubing for General Use.

Available dimensions

K-Tube has the capability to make tubing with the wall thickness and outside diameter combinations in the table below. Tubing with an OD/Wall ratio lower than 20:1 can be drawn to the final dimensions. Tubing with an OD/Wall ratio between 20:1 and 40:1 must be centerless ground to the final dimensions. K-Tube's capabilities are constantly improving, please inquire if your dimensions are outside of the listed dimensions.

Download The 17-7PH K-Tube Technical Data Sheet

Download the 304-304L K-Tube Technical Data Sheet (PDF) to easily share all the details on this page with your team.

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