# Cutting data

Cutting parameter fields, operation types, calculated output values, and the formulas used.

Source: https://support.toolingmetrics.com/en/library/reference/cutting-data/
Updated: 2026-10-29

A **Cutting Data** entry defines the machining parameters for one tool assembly line, one operation type, and one workpiece material. It is the source that the machining calculator pre-populates and the setup sheet prints for each operation.

:::caution[Verify before machining]
Calculated speeds, feeds and depths are starting values. Before you machine, check the tool geometry, units, cutting parameters and the machine's limits against the tool manufacturer's data and your shop's procedures. See section 10 of the [Terms of Service](https://toolingmetrics.com/eng/legal/terms).
:::

## Fields

| Field | Description |
|---|---|
| **Operation Type** | The machining operation this entry applies to. See [Operation types](#operation-types) below. |
| **Material** | The workpiece material from the Materials Library. Used to filter compatible entries in the machining calculator and on project operations. |
| **Unit System** | Metric (mm, m/min) or Inch (in, sfm). All parameter values are stored and displayed in the selected unit system. |
| **Vc** | Cutting speed. m/min (metric) or sfm (inch). Manufacturer-recommended value for this tool-material combination. |
| **fz** | Feed per tooth (milling, drilling, reaming) or feed per revolution (turning, boring, parting). mm or in. |
| **ap** | Axial depth of cut along the tool axis. mm or in. |
| **ae** | Radial engagement as a percentage of the cutting diameter. Milling operations only. |
| **dm** | Workpiece or bore diameter. mm or in. Turning, boring, parting, grooving, and threading only. |

## Calculated outputs

The following values are computed from the inputs above and displayed read-only. See [Formulas](#formulas) for how each is derived.

| Field | Symbol | Unit (metric / inch) | Description |
|---|---|---|---|
| **Spindle Speed** | *n* | rpm | Rotational speed at the working diameter. |
| **Feed Rate** | *vf* | mm/min / in/min | Linear feed speed of the tool or workpiece. |
| **Material Removal Rate** | *Q* | cm³/min / in³/min | Volume of material removed per minute. |
| **Chip Thickness** | *he* | mm / in | Equivalent mean chip thickness. |
| **Cutting Power** | *Pc* | kW / hp | Estimated power at the cutting point. Only shown when the workpiece material has a specific cutting force (*kc*) value defined. |
| **Torque** | *Tc* | Nm / ft·lb | Estimated spindle torque. Only shown when *kc* is available. |

## Operation types

| Group | Operations |
|---|---|
| **Milling** | Face milling, Slot milling, Shoulder milling, Copy milling, Disc milling |
| **Turning** | External turning, Internal turning, Parting-off, Grooving |
| **Threading** | External threading, Internal threading |
| **Hole Making** | Drilling, Step drilling, Deep hole drilling, Cylindrical reaming, Profile reaming, Boring, Counterboring, Countersinking, Trepanning |
| **Broaching** | Circular broaching, Linear broaching |

Trepanning and Broaching entries store Vc, fz, ap, and ae like any other operation, but the machining calculator does not derive Spindle Speed, Feed Rate, or the other Calculated Outputs for these two groups — those fields are blank for these operation types.

## Formulas

### Spindle speed

Applies to all operations:

| Unit system | Formula |
|---|---|
| Metric | *n* = *Vc* × 1000 / (π × *Dw*) |
| Inch | *n* = *Vc* × 12 / (π × *Dw*) |

*Dw* (working diameter) is the effective cutting diameter at the programmed depth. For turning, parting, boring, and threading it equals *dm*. For milling it is derived from tool geometry — see below.

### Working diameter (milling)

| Insert geometry | Formula |
|---|---|
| Square or flat | *Dw* = *Dc* when *ap* ≥ *re* ; *Dw* = *Dc* − 2*re* + 2√(*ap*(2*re* − *ap*)) when *ap* < *re* |
| Ball nose | *Dw* = *Dc* × sin(arccos(1 − 2*ap* / *Dc*)) |
| Angled (κr < 90°) | *Dw* = *Dc* + 2*ap* / tan(κr) |

### Feed rate

| Operation group | Formula |
|---|---|
| Milling, drilling, reaming | *vf* = *n* × *zeff* × *fz* |
| Turning, boring, parting, grooving | *vf* = *n* × *fz* |
| Threading (metric) | *vf* = *n* × *tp* (*tp* = thread pitch in mm) |
| Threading (inch) | *vf* = *n* / *tpi* |

### Material removal rate

| Operation group | Formula (metric) |
|---|---|
| Milling | *Q* = *ap* × *ae* × *Dw* × *vf* / 100,000 (*ae* in %) |
| Turning, boring | *Q* = *Vc* × *ap* × *fz* |
| Parting, grooving | *Q* = *Vc* × *cw* × *fz* (*cw* = cutting width) |
| Drilling | *Q* = *Vc* × *Dc* × *zeff* × *fz* / 4 |
| Reaming, counterboring | *Q* = *Vc* × *ap* × *zeff* × *fz* × (1 − *ap* / *Dw*) |

### Cutting power

Requires the workpiece material to have a specific cutting force value (*kc*).

| Operation group | Formula (metric) |
|---|---|
| Milling | *Pc* = *ap* × *ae* × *Dw* × *vf* × *kc* / 60,000,000 (*ae* in %) |
| Turning, boring | *Pc* = *Vc* × *ap* × *fz* × *kc* / 60,000 |
| Parting, grooving | *Pc* = *Vc* × *cw* × *fz* × *kc* / 60,000 |
| Drilling | *Pc* = *Q* × *kc* / 60,000 |
| Reaming, counterboring | *Pc* = *Vc* × *ap* × *zeff* × *fz* × *kc* × (1 − *ap* / *Dw*) / 60,000 |

### Torque

| Unit system | Formula |
|---|---|
| Metric | *Tc* = *Pc* × 30,000 / (π × *n*) |
| Inch | *Tc* = *Pc* × 16,501 / (π × *n*) |