KEVOS® MAKEOS · Manufacturing
Cutting Speed Adjusted from the Feed and Speed Tables (Turning, Milling, Drilling)
Starting from the optimum and average feed and speed pair in the handbook’s speed tables, what cutting speed, spindle speed and feed rate do I get for my feed, depth and width of cut once the table adjustment factors are applied, and is my feed inside the recommended range for side milling?
The handbook’s method for adjusting the tabulated cutting speeds: V = Vopt × Ff × Fd for turning, drilling, reaming and full slot milling, V = VHSS × Ff × Fd for high-speed steel turning, V = Vopt × Ff × Fd × Far for face milling, and for end, side and slit milling with a partial radial depth the feed range fmax and fmin from the feed factors and the feed factor interpolated between Ff2 at fmin and Ff1 at fmax, with the ratios you need to read the tables, the spindle speed and the table feed rate. The table factors are entered by you.
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How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Operation and adjustment | choice | The operation and the form of the adjustment the handbook gives for it. |
| Optimum feed from the table fopt | mm | The optimum (first) feed of the feed and speed pair in the table, per revolution or per tooth. |
| Optimum speed from the table Vopt (or VHSS) | m/min | The optimum (lower) speed of the pair in the table, or the HSS speed. |
| Average speed from the table Vavg | m/min | The average (higher) speed of the pair in the table. |
| Feed you will use f | mm | The feed per revolution or per tooth you intend to use. |
| Feed factor Ff from the table | Feed factor read from the adjustment table at your feed ratio and speed ratio. | |
| Depth of cut (and lead angle) factor Fd | Depth of cut and lead angle factor read from the adjustment table. | |
| Radial depth of cut factor Far (face and slit milling) | Radial depth of cut factor from the face milling table. | |
| Maximum feed factor for ar/D (Table 15c) | Maximum feed per tooth factor for your ar/D from Table 15c. | |
| Minimum feed factor for ar/D (Table 15c) | Minimum feed per tooth factor for your ar/D from Table 15c. | |
| Feed factor at the maximum feed Ff1 | Feed factor at the maximum feed for your ar/D and speed ratio. | |
| Feed factor at the minimum feed Ff2 | Feed factor at the minimum feed for your ar/D and speed ratio. | |
| Work diameter (turning) or tool diameter | mm | Diameter of the work in turning, or of the drill, reamer or cutter. |
| Teeth on the tool (1 for turning and drilling) | teeth | Number of teeth on the cutter; 1 for turning, drilling per revolution. |
What each input means
Open an input to see what it is, its units, the worked example and the common mistakes, with a small diagram.
What this means: Operation and adjustment
- What it is
- The operation and which form of the handbook speed adjustment applies to it.
- Units and format
- Choose one of 8 options from the list: Turning, carbide and other tools (V = Vopt Ff Fd); Turning, high-speed steel (V = VHSS Ff Fd); Face milling (V = Vopt Ff Fd Far); Full slot end milling (V = Vopt Ff Fd); End or side milling, partial width (interpolated Ff, V = Vopt Ff Fd); Slit milling, feed into the work (V = Vopt Ff Far); Slit or side milling, feed parallel (interpolated Ff, V = Vopt Ff); Drilling, reaming or threading (V = Vopt Ff Fd).
- Example
- The form opens with “Turning, carbide and other tools (V = Vopt Ff Fd)” selected as a worked example. Choose the option that matches your case.
- Effect on the result
- Chooses which factors multiply the table speed.
- Get it right
- Use the partial width choice for end and side milling when the radial depth is less than the cutter diameter.
What this means: Optimum feed from the table fopt
- What it is
- First feed of the optimum and average pair given in the speed table.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 50 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 0.4318 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Divides your feed to give the feed ratio, and sets fmin and fmax.
- Get it right
- Table feeds are in thousandths of an inch; multiply by 0.0254 for mm.
What this means: Optimum speed from the table Vopt (or VHSS)
- What it is
- Lower speed of the optimum and average pair given in the speed table.
- Units and format
- Enter a number in m/min: metres per minute. The form accepts 0.000001 m/min to 10000 m/min. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 187.45 m/min as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The adjusted speed is this times the factors.
- Get it right
- Table speeds are in ft/min; multiply by 0.3048 for m/min. For HSS use the single HSS speed.
What this means: Average speed from the table Vavg
- What it is
- Higher speed of the optimum and average pair given in the speed table.
- Units and format
- Enter a number in m/min: metres per minute. The form accepts 0.000001 m/min to 10000 m/min. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 248.41 m/min as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The speed ratio Vavg ÷ Vopt picks the column in the factor table.
- Get it right
- Use the speed paired with the smaller (average) feed.
What this means: Feed you will use f
- What it is
- Feed per revolution or per tooth that you intend to run.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 50 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 0.381 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Sets the feed ratio and, for side milling, the interpolated feed factor.
- Get it right
- Use the same unit as the table feed, per revolution for turning and drilling, per tooth for milling.
What this means: Feed factor Ff from the table
- What it is
- Feed factor read from the adjustment table at your feed and speed ratios.
- Units and format
- Enter a plain number with no unit. The form accepts 0.000001 to 100. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 1.07 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The adjusted speed rises in proportion.
- Get it right
- Find the feed ratio row and the speed ratio column in the table for the operation.
What this means: Depth of cut (and lead angle) factor Fd
- What it is
- Factor for depth of cut and lead angle read from the adjustment table.
- Units and format
- Enter a plain number with no unit. The form accepts 0.000001 to 100. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 1 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The adjusted speed rises in proportion.
- Get it right
- Read it in the same row as the feed factor, in the column for your depth and lead angle.
What this means: Radial depth of cut factor Far (face and slit m…
- What it is
- Factor for radial depth of cut in face milling and slit milling.
- Units and format
- Enter a plain number with no unit. The form accepts 0.000001 to 100. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 1 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The adjusted speed rises in proportion.
- Get it right
- Read it from the face milling table at your width of cut to cutter diameter ratio.
What this means: Maximum feed factor for ar/D (Table 15c)
- What it is
- Maximum feed per tooth factor for your radial depth to diameter ratio.
- Units and format
- Enter a plain number with no unit. The form accepts 0.000001 to 100. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 4.5 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- fmax = this times the table feed.
- Get it right
- Read it from the maximum feed column of the side milling table at your ar/D.
What this means: Minimum feed factor for ar/D (Table 15c)
- What it is
- Minimum feed per tooth factor for your radial depth to diameter ratio.
- Units and format
- Enter a plain number with no unit. The form accepts 0.000001 to 100. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 3.1 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- fmin = this times the table feed.
- Get it right
- Read it from the minimum feed column of the side milling table at your ar/D.
What this means: Feed factor at the maximum feed Ff1
- What it is
- Feed factor at the maximum feed per tooth for your ar/D and speed ratio.
- Units and format
- Enter a plain number with no unit. The form accepts 0.000001 to 100. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 7.9 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The interpolated feed factor reaches this at fmax.
- Get it right
- Read it from the maximum feed half of the side milling table.
What this means: Feed factor at the minimum feed Ff2
- What it is
- Feed factor at the minimum feed per tooth for your ar/D and speed ratio.
- Units and format
- Enter a plain number with no unit. The form accepts 0.000001 to 100. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 7.01 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The interpolated feed factor starts from this at fmin.
- Get it right
- Read it from the minimum feed half of the side milling table.
What this means: Work diameter (turning) or tool diameter
- What it is
- Diameter of the work in turning, or of the drill, reamer or milling cutter.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 10000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 50 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A larger diameter needs a lower spindle speed for the same cutting speed.
- Get it right
- Use the diameter being cut: the work in turning, the tool otherwise.
What this means: Teeth on the tool (1 for turning and drilling)
- What it is
- Number of cutting teeth on the milling cutter or tool.
- Units and format
- Enter a number in teeth: a whole number of teeth. The form accepts 1 teeth to 500 teeth. Use a whole number. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 1 teeth as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The feed rate is feed × teeth × spindle speed.
- Get it right
- Enter 1 for turning and for drilling with the feed per revolution.
Method and formulas
- Feed ratio = f ÷ fopt and speed ratio = Vavg ÷ Vopt locate Ff (and Fd) in the adjustment table; Vopt is always the lower of the two table speeds.
- Turning, drilling, reaming, full slot: V = Vopt × Ff × Fd. HSS turning: V = VHSS × Ff × Fd. Face milling: V = Vopt × Ff × Fd × Far. Slit milling fed into the work: V = Vopt × Ff × Far.
- End, side and slit milling with a partial radial depth: fmax = max factor × fopt, fmin = min factor × fopt; Ff = Ff2 + (f − fmin) ÷ (fmax − fmin) × (Ff1 − Ff2); Fd is read at f ÷ fmax; V = Vopt × Ff × Fd (slit and side milling: V = Vopt × Ff).
- Spindle speed n = 1000 V ÷ (π D); feed rate = f × z × n.
- Example: the adjusted speed is 200.57 m/min, 1,276.9 rpm.
Limitations
- The adjusted speeds are for the tool life the speed tables are based on (15 minutes for turning, 45 minutes for milling) unless you also apply a tool life factor.
- The factors come from the handbook adjustment tables for your ratios and are entered by you.
- Check the power and rigidity of the machine at the adjusted speed and feed.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Adjust a table cutting speed to your own feed and depth
- Interpolate the feed factor for a side or end milling cut
- Turn the adjusted speed into spindle speed and feed rate
Who it is for
- CNC machinists
- Process planners
- Manufacturing engineers
What you get
- Feed ratio and speed ratio for reading the tables
- Feed range and interpolated feed factor (side and slit milling)
- Adjusted cutting speed
- Spindle speed and feed rate
Interpreting the result
- A feed below fmin rubs and wears the tool early; a feed above fmax risks breaking the edge.
- For side milling the depth factor is read at the feed ratio to fmax, not to fopt.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 1025, 1034–1035, 1040–1042, 1055–1057. Topic reference; no source tables or recommended settings are reproduced.
Learn the Concepts Behind This Tool
These KEVOS® Library readings explain the method this tool uses, with worked examples.
Useful alongside · KEVOS® original book
Cutting speed and spindle speed
What it covers: Convert cutting speed into spindle speed for turning, milling and drilling, handle constant surface speed and spindle limits, and calculate facing time and effective diameter.
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