Zero nut

A zero nut is an ER collet nut with six adjusting screws in it. When the runout you measure is coming from the spindle or the holder rather than the tool, you correct it here instead of pulling the holder — useful on reamers, drills and long-reach end mills where a few microns changes the hole.

Sizes and threads

SizeThread
ER16M22 × 1.5
ER20M25 × 1.5
ER25M32 × 1.5
ER32M40 × 1.5
ER40M50 × 1.5

What it does

AdjustmentSix precision adjusting screws
Target runout0.002 mm
ColletsMade to work with AA grade ultra-precision collets
At speedBalanced clamping force and consistent concentricity under high speed rotation
Where it helps mostExtended tool overhang, reamers, drills, end mills

Procedure

  1. Loosen the adjusting screws
  2. Clamp the tool, then snug the side screws
  3. Measure the current runout
  4. Adjust the side screws until the runout is where you want it
  5. Done

ER collet chucks →

Body diameters (D, D1), gauge lengths (L2, L1) and the set-screw thread (G) are in the printed catalogue and are supplied with the quotation.

Tell us the machine and the workpiece — we quote the right size

Special accessories → · CNC mill tool holders →