Stainless Steel Custom 450
UNS S45000 · AISI/SAE XM-25
Custom 450 (S45000, XM-25, 1.4594) is a martensitic Cr15-Ni6 precipitation-hardening stainless with molybdenum, copper and niobium, supplied annealed and in H900 through H1150 aged tempers as bar, plate and forgings.
Values for the H900 condition
Custom 450 tempers and conditions
Custom 450 is supplied in 8 conditions, soft to hard. H900 is the default FabDigit quotes; the values on this page are for it.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
solution treated ~1040 °C, air cooled (Condition A) | Supply/soft-martensite condition for machining, forming and welding before aging. | 690 | 930 | 15 | 26 HRC | — |
Overaged 621 °C (1150 °F) for 4 h, maximum toughness | Lowest-strength aged temper: highest ductility/toughness and best resistance to chloride SCC. | 725 | 895 | 20 | 28 HRC | — |
Aged 593 °C (1100 °F) for 4 h | Softer over-aged condition for maximum toughness and best SCC performance. | 860 | 965 | 18 | 30 HRC | — |
Aged 4 h at 566 °C | Use when 145 ksi class strength with high toughness and good chloride resistance is wanted. | 930 | 1,000 | 17 | 32 HRC | — |
Aged 552 °C (1025 °F) for 4 h | Over-aged temper for better ductility, toughness and stress-corrosion resistance at ~150 ksi class strength. | 1,000 | 1,070 | 16 | 34 HRC | — |
Aged 4 h at 538 °C | Balanced strength/toughness with improved chloride SCC resistance; common for shafts and valve stems. | 1,100 | 1,170 | 15 | 37 HRC | — |
Aged 4 h at 510 °C | Slight over-age from peak: near-H900 strength with marginally better toughness. | 1,170 | 1,240 | 14 | 40 HRC | — |
H900Default Aged 482 °C (900 °F) for 1 h, peak hardness | Pick for maximum strength and hardness where chloride SCC risk is low. | 1,205 | 1,310 | 14 | 42 HRC | — |
What is Custom 450?
Custom 450 (S45000, XM-25, 1.4594) is a martensitic Cr15-Ni6 precipitation-hardening stainless with molybdenum, copper and niobium, supplied annealed and in H900 through H1150 aged tempers as bar, plate and forgings. It offers higher strength and better corrosion resistance than 17-4 PH plus good weldability, so it is used for shafting, marine and pulp/paper hardware and aerospace structure. H900 gives 1205 MPa yield, 1310 MPa tensile, 14% elongation and 42 HRC; machinability is low (28), cold formability poor (20) and service is capped near 400 °C. 17-4 PH is cheaper and more widely stocked. Custom 450 has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F). Custom 450 has a yield strength of 1,205 MPa (175 ksi) and a tensile strength of 1,310 MPa (190 ksi) — stronger than 99% of stainless steel grades. Elongation at break is 14% and the elastic modulus is 200 GPa (29 Msi).
What is Custom 450 used for?
- Aerospace landing gear components
- Hydraulic shafts and rods
- Pump and valve shafts
- Pulp and paper machine parts
- Marine fasteners and fittings
- Chemical process shafting
- Surgical and instrument components
Advantages
- High strength — 1,205 MPa (175 ksi), better than 99% of stainless steel grades
Limitations
- Limited ductility — 14%, worse than 91% of stainless steel grades
- Limited formability — 20/100, worse than 86% of stainless steel grades
- Low fracture toughness — 80 MPa·√m (72.8 ksi·√in), worse than 79% of stainless steel grades
- Limited service temperature — 400°C (752 °F), worse than 78% of stainless steel grades
Custom 450 properties
Typical room-temperature values for Custom 450-H900; bars are the position among stainless steel grades.
Physical3
Custom 450 has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
Custom 450 has a yield strength of 1,205 MPa (175 ksi) and a tensile strength of 1,310 MPa (190 ksi) — stronger than 99% of stainless steel grades. Elongation at break is 14% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
Custom 450 is rated for continuous service to 400°C (752 °F). It conducts heat at 15.9 W/m·K (9.19 BTU/hr·ft·°F), better than 55% of stainless steel grades. Thermal expansion is 10.6 µm/m·K (5.89 µin/in·°F).
Electrical3
Custom 450 conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), worse than 62% of stainless steel grades.
Sustainability4
Producing a kilogram of Custom 450 takes about 57 MJ of energy and emits 4.6 kg of CO₂ — more than 62% of stainless steel grades. Typical recycled content is 40%.
Manufacturability7
Custom 450's machinability is poor (28/100, worse than 79% of stainless steel grades); weldability good (60/100); formability poor (20/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. Custom 450 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Custom 450
Is Custom 450 easy to machine?
Machine in Condition A or at H1050–H1150 with rigid setups, positive-rake carbide, heavy feeds and flood coolant; work-hardens and galls like 17-4PH, so avoid dwelling and light finishing passes.
Can Custom 450 be welded?
Readily GTAW/GMAW/EBW welded without preheat using matched or 630/17-4PH filler; re-solution treat and age for full properties, or age-only for near-parent strength — no post-weld cracking issue thanks to Nb stabilization.
Can Custom 450 be formed, bent or molded?
Cold form only in the annealed condition with generous radii and springback allowance; hot work 1150–1200 °C and finish above 950 °C, then solution treat before aging.
Manufacturability
The process limits FabDigit applies to Custom 450. Every Custom 450 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Fair28 / 100 |
|---|---|
| ISO material group | M.1 |
| Cutting speed (rough / finish) | 150 / 180 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1.5 mm |
| Drill depth limit | 4× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Fair20 / 100 |
|---|---|
| Weldability | Better60 / 100 |
Custom 450 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C | ≤ 0.05 | 0.03 |
| Mn | ≤ 1 | 0.4 |
| Si | ≤ 1 | 0.4 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Cr | 14 – 16 | 15 |
| Ni | 5 – 7 | 6 |
| Mo | 0.5 – 1 | 0.75 |
| Cuprincipal precipitation hardener | 1.25 – 1.75 | 1.5 |
| Nb8 × C minimum (Cb stabilization) | ≈ 0.3 | 0.3 |
| Fe | balance |
What surface finishes work on Custom 450?
Passivate per ASTM A967 (nitric or citric) after machining; takes a fine polish and can be electropolished, chrome- or nickel-plated — bake after plating to avoid hydrogen embrittlement at high hardness.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
Organic Coating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel Custom 450 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- S45000
- AISI / SAE
- XM-25
- Also called
- Custom450
- Similar grades
- 1.4594
How much does Custom 450 cost?
Custom 450 is a premium-cost stainless steel ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Custom 450 — frequently asked
What is Custom 450 used for?
Custom 450 is typically used for aerospace landing gear components, hydraulic shafts and rods, pump and valve shafts, pulp and paper machine parts, marine fasteners and fittings and chemical process shafting. In short: tough custom PH stainless.
What is the yield strength of Custom 450?
Custom 450 has a typical yield strength of 1,205 MPa (175 ksi) and a tensile strength of 1,310 MPa (190 ksi) — stronger than 99% of stainless steel grades. Strength varies by condition: see the 8 listed tempers.
Is Custom 450 easy to machine?
Not especially — machinability is rated poor (28/100, worse than 79% of stainless steel grades). Machine in Condition A or at H1050–H1150 with rigid setups, positive-rake carbide, heavy feeds and flood coolant; work-hardens and galls like 17-4PH, so avoid dwelling and light finishing passes.
Can Custom 450 be welded?
Yes — weldability is rated good (60/100). Readily GTAW/GMAW/EBW welded without preheat using matched or 630/17-4PH filler; re-solution treat and age for full properties, or age-only for near-parent strength — no post-weld cracking issue thanks to Nb stabilization.
What surface finishes work on Custom 450?
Passivate per ASTM A967 (nitric or citric) after machining; takes a fine polish and can be electropolished, chrome- or nickel-plated — bake after plating to avoid hydrogen embrittlement at high hardness.
Can Custom 450 be formed, bent or molded?
Cold form only in the annealed condition with generous radii and springback allowance; hot work 1150–1200 °C and finish above 950 °C, then solution treat before aging.
What is the maximum service temperature of Custom 450?
Custom 450 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Custom 450-H900 and Custom 450-H1150?
H900 is the default condition — pick for maximum strength and hardness where chloride SCC risk is low. H1150: lowest-strength aged temper: highest ductility/toughness and best resistance to chloride SCC. Yield strength is 1,205 MPa in H900 versus 725 MPa in H1150.
How much does Custom 450 cost?
Custom 450 is a premium-cost stainless steel ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in Custom 450?
Yes — Custom 450 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A564/A564M — Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars and Shapes (Type XM-25) — ASTM International (2019)
- ASTM A693 — Precipitation-Hardening Stainless and Heat-Resisting Steel Plate, Sheet, and Strip — ASTM International (2016)
- Custom 450 Stainless (UNS S45000) alloy datasheet — Carpenter Technology (2020)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- MMPDS-16 — Precipitation-hardening stainless steels — Battelle/FAA (2021)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.