CNC Calculator
Feed & Speed Optimization Tool
Input Parameters
Calculated Results
RPM = (Vc × 1000) / (π × D)
Feed = RPM × Fz × Z
Important Note
Always verify calculated values against your machine's specifications and material recommendations. These calculations provide theoretical values and should be adjusted based on your specific machining conditions.
Cutting Speed Reference Guide
Recommended cutting speeds (Vc in m/min) for different tool and material combinations
| Tool Type |
Fz (mm)
Feed/Tooth
|
Cutting Speed Vc (m/min) | ||||
|---|---|---|---|---|---|---|
| Normal Steel |
Medium Hard (42CrMo4) |
Hard Steel | Stainless | Aluminium | ||
| U-Drills | 0.06-0.14 | 140 | 90-120 | 40-80 | 110 | 200 |
| Hard Metal End Mills | 0.03-0.2 *** | 120 | 80-100 | 40-60 | 50 | 200-300 |
| Hard Metal Drills | 0.15-0.25 | 100-120 | 70-90 | 40-50 | 40 * | 180-200 |
| HSS Drills | 0.08-0.12 | 10-20 | 7-15 | 3-5 ** | 5-7 | 30-40 |
| Turning Inserts | See insert data | 200-250 | 140-150 | 40-80 | 100-115 | 250-350 |
| Milling Inserts | See insert data | 180-200 | 140-150 | 40-80 | 100-115 | 250-350 |
| High Speed Milling Inserts | 0.3-1.5 **** | 180-200 | 140-150 | 40-80 | 100-115 | 250-350 |
U-Drills
Hard Metal End Mills
Hard Metal Drills
HSS Drills
Turning Inserts
Milling Inserts
High Speed Milling Inserts
Internal Coolant Requirement
If you don't have internal coolant, reduce the Vc (RPM) by approximately 50% for the following tools:
- U-Drills
- Hard Metal Drills
Internal coolant is essential for proper chip evacuation and tool life in deep hole drilling operations.
Notes:
* Not recommended to drill into stainless steel with hard metal drills
** HSS drills don't handle hard steel very well - better to use U-drills or hard metal drills
*** Hard metal end mills: Fz depends on cut depth - higher values for full cuts, lower for light cuts (≤10% tool engagement)
**** High speed milling: Optimal Fz = 0.8-1.0mm for normal/medium hard steel, 0.5mm for stainless steel
Important Guidelines:
- Hard Steel: Values depend on actual hardness - always start conservatively and adjust based on tool performance
- Ranges: Start with lower values and increase gradually based on results and finish quality
- Manufacturer Data: Always consult tool manufacturer specifications for optimal performance
- Adjustments: Modify values based on depth of cut, tool condition, coolant availability, and machine rigidity
- Safety First: These are baseline recommendations - actual values may vary based on your specific application