Grade dossier
Custom 455 Stainless Steel for Age-Hardened Strength
A Carpenter-developed age-hardening grade combining high strength, corrosion resistance and relatively simple heat treatment for aerospace and industrial parts.
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 | 0.050 max |
|---|---|
| Mn | 0.50 max |
| Si | 0.50 max |
| P | 0.040 max |
| S | 0.030 max |
| Cr | 11.00-12.50 |
| Ni | 7.50-9.50 |
| Mo | 0.50 max |
| Cu | 1.50-2.50 |
| Ti | 0.80-1.40 |
| Nb+Ta | 0.10-0.50 |
Properties with context
Minimums, typical indicators and delivered condition
Specified annealed flat-product values
| Annealed/solution-treated | Starting condition; verify machining route |
|---|---|
| H900 | Very high strength with condition-specific toughness |
| H950 | Common strength-toughness balance |
| Higher aging temperatures | Lower strength with increased toughness/SCC margin |
Selection indicators
| Density | about 7.76 g/cm3 |
|---|---|
| Hardening | Low-temperature aging after solution treatment |
| Maximum hardness | about 50 HRC depending on condition |
| Procurement rule | Use UNS, trademark, form and aging condition |
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 Custom 455 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 fittings and fasteners
Valve components, shafts and springs
Medical and industrial tooling after qualification
High-strength parts with complex machining
Reasons to stop and review
Using the trademark without UNS identity
Applying one condition property to another
Welding without a qualified final heat treatment
Substituting Custom 465 without design approval
Fabrication route
Protect properties through cutting, forming and welding
State S45500 and the applicable AMS/ASTM specification.
Plan machining, welding and aging as one route.
Control decarburization, scale and surface contamination.
Verify final hardness, tensile and toughness requirements.
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 and wire to AMS 5617
ASTM A564/A564M XM-16 products
Sheet and strip to ASTM A693
Forgings and machined aerospace components
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.
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IMAGE PLACEHOLDER
IMAGE PLACEHOLDER
Interactive selection check
Test Custom 455 against the controlling question
Procurement FAQ
Questions to close before placing the order
Is Custom 455 stainless steel magnetic?
Magnetic response depends on microstructure and delivered condition.
Can Custom 455 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?
No. Custom 455 is a trademarked S45500 alloy and final properties depend on aging condition and product specification.
What should a Custom 455 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
Carpenter Technology Custom 455 official datasheet
AMS 5617 requirements for applicable S45500 products
ASTM A564/A693 requirements for XM-16 product forms
Qualified heat-treatment and final-condition inspection plan