17-7 PH, UNS S17700, is a semi austenitic precipitation hardening stainless supplied mainly as sheet and strip. In the annealed Condition A it is austenitic and formable; a conditioning treatment transforms it to martensite and a final age develops strength approaching 200 ksi.
That sequence lets a part be formed in a soft, ductile condition and hardened afterward, which suits springs, clips, diaphragms, bellows and formed high strength sheet hardware.
We stock 17-7 PH in Condition A, CH900, RH950 and TH1050, in sheet, strip and wire, with blanking and shearing available.
Sizes and stock
- Round bar: up to 5" DIA
- Sheet / plate: up to 1.5" THK
- Coil / foil: from .0005" THK
- Wire: from .005" DIA
- Tube: various sizes
- Forgings: available by request
Processing capabilities
- Condition and precipitation hardening (H900 through H1150) to your call-out
- Shearing, waterjet, laser and saw cut blanks
- Centerless grinding, turning and polishing
- Penetrant dye and ultrasonic inspection, chemical assay and physical testing
Supplied in any temper or aged condition to your call-out. Stock is not held in aged tempers; we heat treat to order.
Specifications
Material is released to the applicable specification with mill test reports and, on request, independent lab verification.
Why engineers specify 17-7 PH
- Formable when annealed, very strong after hardening
- High spring properties in thin section
- Good corrosion resistance compared with carbon spring steels
- Available in the common CH900, RH950 and TH1050 conditions
Nominal chemistry
Percent by weight, nominal composition per the governing specification. The mill test report for your heat is the controlling document.
Typical mechanical properties
| Condition | Tensile strength | Yield strength | Elongation | Hardness |
|---|---|---|---|---|
| Condition A | ~130 ksi | ~40 ksi | ~35% | - |
| TH1050 | 177 ksi min | 150 ksi min | 6% min | - |
| RH950 | 200 ksi min | 175 ksi min | 6% min | - |
| CH900 | 220 ksi min | 205 ksi min | 1% min | - |
Typical published values for reference only, not for design. Properties vary with section size, product form and processing. Order to the specification and condition your drawing requires.
Typical applications
- Springs, clips and retainers
- Diaphragms and bellows
- Formed sheet structure
- Aerospace fittings in thin section
Fabrication notes
Machining
Austenitic grades work harden quickly, so use positive rake tooling, rigid setups, generous feed and flood coolant rather than light dwelling cuts. Martensitic and precipitation hardening grades machine most easily in the annealed or solution treated condition and are aged after rough machining.
Welding
Weldable by GTAW, GMAW, resistance and electron beam methods with matching or over alloyed filler. Stabilized and low carbon grades resist sensitization in the weld zone. Precipitation hardening grades are normally welded in the solution treated condition and aged afterward.
Forming
Sheet and strip form well in the annealed condition; cold worked tempers trade formability for strength. Allow for springback and, where specified, an intermediate anneal between draws.
17-7 PH compared with similar grades
301 full hard
Cold worked strength in sheet without a hardening cycle, less strength after forming.
17-4 PH
Bar and forging grade, martensitic in the solution treated condition, not a formable sheet product.
Designations and cross reference
- Material family
- Stainless Steel
- Werkstoff (W.Nr)
- 1.4568
- EN designation
- X7CrNiAl17-7
- Series
- Precipitation Hardening
Working from an obsolete, foreign or superseded designation? Send it over and we will cross reference it to a current grade and specification.
Quality, testing and traceability
Supplied with mill test reports and heat traceability, with penetrant dye, ultrasonic, chemical assay, hardness, corrosion and mechanical testing available on request.
We are AS9100D and ISO 9001:2015 registered. If our stock does not already carry the inspection your specification requires, we can quote the material with that work performed. More on our quality system
Available forms
17-7 PH frequently asked questions
What is 17-7 PH?
17-7 PH, UNS S17700, is a semi austenitic precipitation hardening stainless supplied mainly as sheet and strip. In the annealed Condition A it is austenitic and formable; a conditioning treatment transforms it to martensite and a final age develops strength approaching 200 ksi.
What forms is 17-7 PH available in?
We supply 17-7 PH in bar, sheet, plate, coil, foil, wire, tube, forging. Custom sizes are converted from billet, and we can provide saw cut, waterjet or near net blanks so material arrives closer to your finished part.
What is the UNS or equivalent designation for 17-7 PH?
17-7 PH is designated Werkstoff 1.4568, EN X7CrNiAl17-7. If your drawing calls out an obsolete or foreign designation we can cross reference it and confirm the equivalent before you order.
What specifications can 17-7 PH be supplied to?
Commonly ordered specifications include AMS 5528, AMS 5529, AMS 5568, AMS 5644, AMS 5678. Material is released to the specification and condition on your purchase order, with mill test reports supplied as standard.
What conditions can 17-7 PH be ordered in?
We can supply Condition A, TH1050, RH950, CH900. If our stock is not already in the condition you need, we can quote it with the heat treatment performed before shipment.
Can you cut 17-7 PH to size?
Yes. Saw cutting, waterjet, laser and shearing are available, along with trepanning, gun drilling, lathe turning and CNC machining, so you can order blanks or rough machined pieces rather than full lengths.
Do you provide test reports and additional testing on 17-7 PH?
Every order ships with mill test reports and heat traceability. If your print calls for ultrasonic inspection, penetrant dye, magnetic particle, chemical assay, micrography, hardness or mechanical testing and our stock does not already carry it, we can quote the material with that work performed.
Can 17-7 PH be supplied to DFARS domestic melt requirements?
Tell us at quote stage if the order is DFARS or domestic melt restricted and we will confirm availability against that requirement before you commit.
What do you need to quote 17-7 PH?
Grade, form, dimensions, quantity, specification and condition, plus any testing or certification requirements and the date you need it. Send a drawing if you have one. Quotes are typically ready within 24 hours.
How does 17-7 PH compare with 301 full hard?
Cold worked strength in sheet without a hardening cycle, less strength after forming.