Nickel Alloy Feeds & Speeds Chart
Quick-look reference data for nickel-alloy milling across Inconel, Hastelloy, and Monel. Best used as a first-pass carbide chart before you validate coolant, engagement, and work-hardening risk in the calculator.
Need Exact Nickel-Alloy Milling Numbers?
Use this chart for a fast first pass. Then move to the Inconel calculator when tool diameter, coating choice, coolant strategy, or work-hardening risk need a setup-specific answer.
What This Chart Covers Best
First-pass carbide SFM and chip-load ranges for nickel-alloy milling, especially when the job is Inconel 718 roughing, conservative finishing, or a quick Monel/Hastelloy comparison.
Where It Needs Backup
Turning, drilling, and boring need feed-per-rev logic, insert-style decisions, and breakthrough or stability rules. Ceramic roughing also needs a process-specific sheet instead of a carbide chart.
Best Next Links
Branch to the Inconel calculator, chip-load calculator, drilling calculator, or turning calculator when the setup gets specific.
Inconel 718 / 625 (Age Hardened)
The dominant aerospace superalloy. Inconel 718 retains tensile strength above 650°C (1200°F) and work hardens aggressively. Solution-treated (ST) machines slightly easier than age-hardened (AH, 40-44 HRC).
| Condition | Operation | SFM (Coated Carbide) | Chip Load (1/2" EM) |
|---|---|---|---|
| Solution Treated | Roughing | 70 - 120 | 0.002" - 0.004" |
| Solution Treated | Finishing | 100 - 150 | 0.001" - 0.002" |
| Age Hardened (40+ HRC) | Roughing | 40 - 80 | 0.0015" - 0.003" |
| Age Hardened (40+ HRC) | Finishing | 60 - 100 | 0.0008" - 0.0015" |
Hastelloy C-276 / C-22
Corrosion-resistant superalloy for chemical processing, pollution control, and flue gas desulfurization. Extremely gummy — generates long, stringy chips that wrap around the tool. Aggressive chip breaking is essential.
| Alloy | Operation | SFM (Coated Carbide) | Chip Load (1/2" EM) |
|---|---|---|---|
| C-276 | Roughing | 40 - 80 | 0.002" - 0.003" |
| C-276 | Finishing | 60 - 100 | 0.0008" - 0.0015" |
| C-22 | Roughing | 35 - 70 | 0.0015" - 0.003" |
Monel 400 / K-500
Nickel-copper alloy for marine, chemical, and oil & gas applications. Easier to machine than Inconel but still work hardens. K-500 is age-hardenable to 35 HRC and requires ceramic or CBN inserts for interrupted cuts.
| Alloy | Operation | SFM (Coated Carbide) | Chip Load (1/2" EM) |
|---|---|---|---|
| Monel 400 | Roughing | 80 - 150 | 0.002" - 0.004" |
| Monel 400 | Finishing | 120 - 200 | 0.001" - 0.002" |
| Monel K-500 (Aged) | Roughing | 50 - 100 | 0.0015" - 0.003" |
Superalloy Survival Rules
Nickel alloys generate extreme heat at the cutting edge (800–1100°C) and work harden within microseconds.
- High-pressure coolant: Usually the best starting point for productive nickel-alloy milling. Conservative flood setups can still work if you back down speed and keep chip control stable.
- Never rub: Maintain positive chip load at all times. A single dwell creates a work-hardened layer that destroys subsequent passes.
- Ceramic inserts: Treat ceramic roughing as its own process sheet. Do not translate these carbide chart rows directly into ceramic speed targets.
- Climb milling: Usually the safer nickel-alloy starting point because it helps limit rubbing and exit-side work hardening.
Frequently Asked Questions
What SFM should I use for Inconel 718?
For coated-carbide milling, solution-treated 718 often starts around 70–120 SFM roughing and 100–150 SFM finishing. Age-hardened material usually drops below that. If the job is turning, drilling, or ceramic roughing, switch to the dedicated workflow instead of stretching this milling chart.
Why does Inconel destroy cutting tools so fast?
Nickel superalloys retain strength at cutting temperatures (800°C+), causing extreme flank wear. They also work harden instantly when rubbed, creating a harder surface layer that accelerates tool failure.
Should I use coolant when machining Inconel?
For carbide milling, yes: high-pressure coolant is usually the strongest starting point because it helps with heat removal and chip control. If you are roughing with ceramics, treat that as a separate ceramic-specific process instead of assuming the same coolant rules as this carbide chart.
What is the best coating for machining Inconel?
AlTiN or TiAlN with high aluminum content (65%+ Al). These coatings form a protective aluminum oxide layer at cutting temperatures. Multi-layer nano-composite coatings (e.g., nACo) are the premium choice.
What is the difference between Inconel and Hastelloy for machining?
Both are nickel superalloys. Inconel 718 is precipitation-hardened (stronger, harder). Hastelloy C-276 is solution-strengthened (softer but gummier, produces longer stringy chips). Hastelloy requires more aggressive chip breaking.