Advanced Calculator Inputs
Example Data Table
| Operation | Start Size | Final Size | Max Pass | Finish Pass | Typical Result |
|---|---|---|---|---|---|
| Turning | 50 mm diameter | 46 mm diameter | 0.8 mm radial | 0.2 mm | 4 passes |
| Milling | 25 mm height | 22 mm height | 1 mm axial | 0.3 mm | 4 passes |
| Boring | 38 mm diameter | 42 mm diameter | 0.5 mm radial | 0.15 mm | Review setup direction |
Formula Used
Turning or boring radial depth:
Depth of cut = (Starting diameter - Final diameter) / 2 + Allowance
Milling, facing, or slotting depth:
Depth of cut = Starting height - Final height + Allowance
Number of passes:
Passes = Ceiling(Total depth of cut / Planned depth per pass)
Milling feed rate:
Feed rate = Feed per tooth × Number of teeth × RPM
Turning feed rate:
Feed rate = Feed per revolution × RPM
Milling material removal rate:
MRR = Depth of cut × Width of cut × Feed rate
Estimated spindle power:
Power kW = MRR × Specific cutting force / (60,000,000 × Efficiency)
How to Use This Calculator
- Select metric or imperial units.
- Choose the machining operation.
- Enter the starting size and final size.
- Add any stock allowance if needed.
- Enter the maximum safe depth per pass.
- Add a finish depth if you want a lighter final pass.
- Enter feed, speed, cutter, and machine values.
- Press the calculate button.
- Review depth, passes, feed rate, removal rate, and power.
- Download the result as CSV or PDF when needed.
Depth of Cut Planning Guide
What Depth of Cut Means
Depth of cut is the amount of material removed in one pass. It is one of the most important machining values. It affects tool load, heat, power, finish, and cycle time. A deeper cut can remove stock faster. It can also increase vibration and tool wear. A shallow cut may improve finish. It may also waste time during roughing.
Why Pass Planning Matters
Pass planning helps balance speed and control. Roughing passes remove most of the stock. A finishing pass improves size and surface quality. This calculator separates rough depth and finish depth. That makes the plan easier to review. It also helps prevent overloading smaller machines.
Turning and Boring
Turning depth is usually radial. If a shaft diameter drops from 50 mm to 46 mm, the radial removal is 2 mm. The diameter changes by twice the radial depth. This calculator handles that difference automatically. Boring follows the same radial idea. Always confirm the cutting direction before using the values.
Milling and Slotting
Milling often uses axial depth and radial width. The calculator uses both values for material removal rate. Feed per tooth, teeth, and spindle speed set the feed rate. A full-width slot usually needs a lighter depth. Side milling may allow a different balance. Tool diameter also affects cutting speed.
Practical Use
Use the output as a planning estimate. Check machine rigidity before cutting. Reduce depth for long tools, hard materials, or weak setups. Increase depth only when the machine, tool, and fixture allow it. Keep notes from real cuts. Shop data improves every future estimate.
FAQs
1. What is depth of cut?
Depth of cut is the thickness of material removed by a tool in one pass. In turning, it is usually measured radially. In milling, it is often the axial depth into the workpiece.
2. Why is turning depth divided by two?
Turning removes material from the radius, while diameter changes across both sides. A 4 mm diameter reduction equals a 2 mm radial depth of cut.
3. What is a finish depth?
A finish depth is a smaller final pass. It helps improve size control, surface finish, and tool mark consistency after roughing passes remove most stock.
4. What does material removal rate mean?
Material removal rate estimates how much stock is removed per minute. It helps compare productivity and gives a useful clue about cutting load.
5. Can I use inches?
Yes. Select imperial units. Enter sizes, feed, width, and depth in inches. The calculator will show matching imperial outputs where suitable.
6. What is specific cutting force?
Specific cutting force estimates material resistance. Hard materials need higher values. Steel is often planned near 1800 N/mm², but actual values vary by grade and tooling.
7. Is the power result exact?
No. It is an estimate. Real power depends on tool geometry, wear, coolant, material grade, machine condition, and actual chip formation.
8. Why are many passes sometimes recommended?
Many passes appear when total stock is large or maximum depth per pass is small. This may protect the tool, machine, fixture, and workpiece.