Setup / Workshop reference
Collets, insertion & tool stickout
Separate the length held inside the collet from the length exposed below it.
In everyday language
Separate holding size from cutting size
The shank is the part held by the machine. The collet is the gripping sleeve. Stickout means how far the tool extends from its holder.
On the tool drawing, circle the shank size and underline the cutting width. They are separate measurements.
What to notice: Match the exact holder and follow the maker's insertion instructions. Extending a tool farther changes the setup.
Are a 6 mm shank and a quarter-inch shank identical?
No. A quarter inch is 6.35 mm. Use the correctly specified compatible holder; do not assume near sizes are interchangeable.
No need to know the vocabulary first
A few words, explained
- Collet
- The gripping sleeve that holds the shank of a cutting bit.
- Shank
- The part of a cutting bit held by the machine, distinct from its cutting diameter.
- Stickout
- How far a tool extends from its holder.
- Spindle
- The rotating assembly that turns the cutting tool.
- CNC
- Computer numerical control: a computer directs a cutting machine.
- Workholding
- The way you keep a piece securely in place while working on it.
1 more words used on this page
- Flutes
- Grooves along a cutting bit. Check the manufacturer's stated number of cutting edges for calculations.
How it works
The collet grips the approved plain shank. Stickout is the exposed distance from the holder to the tip; extra reach can reduce rigidity and clearance.
When to consider it
Use the correct collet system and exact compatible shank size. Similar inch and metric sizes are not interchangeable by assumption.
Where it does not apply
Never grip the cutting flutes or improvise a shim. Do not copy a universal insertion, pull-back or tightening value from another spindle.
Before the first cut
- Isolate power using the equipment procedure; clean and inspect the collet, nut and shank.
- Follow the exact holder assembly, engagement, clearance and torque instructions. Keep the gripping zone on the plain shank.
- Keep only the permitted reach needed for the job. Check tool-body and holder clearance, remove setup tools, then re-establish tool length or Z zero as required.
If the result looks wrong
Stop the machine and make it safe to inspect before checking the tool or workpiece.
Tool appears to slip
Stop using the setup. Inspect compatibility, contamination, wear and the specified assembly procedure.
Chatter after changing reach
Review stickout, tool condition and workholding; a previous setting is not validation for a changed assembly.
Use the matching calculator
Calculator outputs describe geometry, time or cost—not permission to operate at those values.
Make the setup repeatable
In Machine & Bit Settings, keep these details in the standard fields, additional fields and setup notes. Record a test date only after testing that exact setup.
- Collet system and shank size
- Measured stickout with units
- Manufacturer instructions URL
- Tool-length / Z-reference procedure
No cutting settings are automatically supplied or saved by this guide.
References & exact specifications
These public references explain the tool families or software features. Locate your exact part number and machine manual before setup; product families are not interchangeable.
Guidance reviewed September 2026. Diagrams are original simplified explanations, not manufacturer drawings.