WoodWorkCalc

Bits / Workshop reference

Compression bits & transition length

Understand where the upcut tip changes to downcut—and why shallow passes may still tear the top face.

How it works

The lower upcut section and upper downcut section act toward one another. Both faces benefit only when the appropriate sections engage those faces.

When to consider it

Compare compression tooling for through-profiling double-sided veneered or laminated sheet goods supported by the tool specification.

Where it does not apply

Compression is not permission to cut full depth. A shallow pass with only the upcut section at the top face can still lift its fibers.

ShankTipAxial action
Upper and lower cutting actions point toward the transition. Its actual location comes from the tool drawing. Concept diagram, not to scale; guards and fixtures are omitted.

Before the first cut

  1. Read the exact upcut length and transition location from the tool drawing.
  2. In CAM, compare that transition with actual stock thickness and the engagement at every pass.
  3. If the required engagement exceeds the machine, tool or workholding limits, choose another tool or a supported multi-tool strategy; do not force a deeper cut.

Review collet engagement & stickout · Review material setup & zero

If the result looks wrong

Stop the machine and make it safe to inspect before checking the tool or workpiece.

Top veneer still tears

Check whether the top face is being cut by the upcut section, especially during entry and early passes.

Thin sheet has poor edges

Check that the transition can lie within the material; a different geometry may be required.

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.

  • Upcut length / transition
  • Actual sheet thickness
  • Entry and pass strategy
  • Top and bottom test results

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.

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