Grade dossier
15-5 PH Stainless Steel for Transverse Toughness
A precipitation-hardening grade related to 17-4 PH but compositionally balanced for low delta ferrite, transverse toughness and forgeability.
Identity before substitution
Define the grade, product and condition together
A familiar grade name is not a complete purchase specification. Product form, controlling standard, dimensions, condition, finish, certification and service environment determine whether the delivered material is suitable.
Composition control
ASTM A240/A240M flat-product chemistry
Limits are not heat analysis targets
The table summarizes grade limits commonly used for plate, sheet and strip. Pipe, tube, bar, forgings and cast products can be governed by different specifications. Always place the product standard and edition on the purchase order.
| C | 0.070 max |
|---|---|
| Mn | 1.00 max |
| Si | 1.00 max |
| P | 0.040 max |
| S | 0.015 max |
| Cr | 14.00-15.50 |
| Ni | 3.50-5.50 |
| Cu | 2.50-4.50 |
| Nb+Ta | 0.15-0.45 |
Properties with context
Minimums, typical indicators and delivered condition
Specified annealed flat-product values
| Condition A | Solution treated; age before using final properties |
|---|---|
| H900 | High-strength condition |
| H1025 | Balanced strength and toughness |
| H1150 | Overaged condition for ductility and SCC margin |
Selection indicators
| Density | about 7.8 g/cm3 |
|---|---|
| Hardening | Single-step low-temperature aging |
| Directionality | Designed for improved transverse toughness |
| Procurement rule | Condition and product form are mandatory |
Values depend on product form, thickness, test orientation, condition and governing edition. Use the mill test certificate and the purchase specification for acceptance, not a web table alone.
Selection boundary
Where 15-5 PH belongs and where to escalate
Grade selection is an environmental decision, not a popularity contest. Review the complete medium, temperature, geometry, fabrication, cleaning and inspection requirements.
Good reasons to evaluate it
Aircraft structural and forged components
Valve bodies, shafts and fasteners
High-strength corrosion-resistant parts
Components needing transverse toughness
Reasons to stop and review
Treating 15-5 and 17-4 as automatic substitutes
Using generic PH properties without condition
Welding without final heat-treatment planning
Ignoring forging orientation and test direction
Fabrication route
Protect properties through cutting, forming and welding
State solution-treatment and aging condition.
Qualify welding and post-weld aging.
Control forging reduction, orientation and test direction.
Verify hardness and mechanical tests in final condition.
Supply definition
Product form changes the applicable requirements
Do not send an RFQ that names only the grade. State form, governing standard, dimensions, tolerances, finish, edge or end condition, quantity, certification and inspection.
Bar to ASTM A564/A564M or AMS 5659
Forgings to ASTM A705/A705M or AMS 5658
Sheet and strip to ASTM A693 / AMS 5862
Aerospace billets and machined parts
Certificate checkpoint
Request heat identity, chemical analysis, mechanical results and compliance to the exact product specification. Add PMI, corrosion testing or supplementary examination only when the application requires it.
Interactive selection check
Test 15-5 PH against the controlling question
Procurement FAQ
Questions to close before placing the order
Is 15-5 PH stainless steel magnetic?
Magnetic response depends on microstructure and delivered condition.
Can 15-5 PH replace another grade?
Only after checking the governing standard, composition, mechanical properties, corrosion exposure, fabrication route and certification. A commercial name is not a substitution approval.
Does the table apply to every product form?
Not automatically. The values shown use flat-product requirements as a reference. Other forms can use different product standards, dimensions and tests.
What should a 15-5 PH RFQ include?
Product form, standard and edition, UNS or EN designation, dimensions, tolerances, finish, quantity, service, fabrication, certificate and inspection requirements.
Sources, scope and RFQ
Use traceable grade data, then specify the actual product
ASTM A564/A705/A693 requirements for UNS S15500
Carpenter Technology 15Cr-5Ni official datasheet
Applicable AMS 5658/5659/5862 product specification
Design allowables for the certified material and condition