Kill chatter marks and swirl — for the finish you need.
A bad finish is a symptom — chatter, the wrong floor geometry, runout, or the wrong edge. Each one has a specific fix, and the right geometry gets the finish without a secondary operation.
Why it happens — and the fix
1Chatter marks on walls
Use a variable-helix tool to damp the vibration, and Mirror Edge geometry on thin walls and deep pockets (over 3:1 length-to-diameter) — it's purpose-built to eliminate chatter and leaves a finish far better than a chattering cut. On necked aluminum tools, take an axial depth deeper than the corner radius to quiet the cut.
2Swirl marks on floors
Wiper Flats clean up the swirl and give a better floor finish — just skip them on thin floors, where the added surface contact isn't worth it.
3Staircase marks and stress risers on necked tools
The Feather Blend transition smooths the step from cutting diameter to neck diameter, reducing staircase marks, stress risers, and the swirl lines that show up when plunging.
4Burrs and torn edges
Climb mill, take a light finishing pass with a high-flute-count finisher, and use a honed (T-Process) edge in steel and alloys. For ball-end finishing, drop the feed about 10%.
5Runout reaching the part
Finish quality starts at the spindle. RobbJack grinds to an h4 shank and holds runout under .0002", and offers ER solid extensions and Accuhold holders held to the same, so the accuracy actually reaches the cut.
The proof
- < .0002"
- runout (TIR) — tightest in the industry
- Mirror Edge
- patented anti-chatter geometry
- Feather Blend
- smooth neck transition, no staircase
Dig deeper
Not sure where to start?
Send us your toughest part. Our application engineers will recommend the tool and the numbers.