Compensator holes


  • To reduce the often long machining time while achieving a high degree of size consistency.
  • To eliminate rings in the bore, produced by the rough pass reamer that are often stuck in the component and need to be removed manually.


The new process strategy and technology replace straight flute tools with helix tools to eliminate the problem with rings. The reinforced core diameter and extra guide pads give a straight hole with excellent size consistency.


In addition, the cycle time is often reduced by more than 50 %.


Machining process


 Step 1: SC twist drill


Step 1: Solid carbide twist drill

Drawing no. 289412.1200, N = 3881 rpm, Fn = 0.25 mm/rev.


Step 2: SC 3-flute step drill 


Step 2: Solid carbide 3-flute step drill

Drawing no. 212891/999999, N = 2000 rpm, Fn = 0.4 mm/rev.


Step 3: SC 3-flute step drill


Step 3: Solid carbide 3-flute step drill

Drawing no. 212851/999999, N = 2160 rpm, Fn = 0.35 mm/rev.


Step 4: SC drill


Step 4: Solid carbide drill

Drawing no. 212120/999997, N = 2158 rpm, Fn = 0.35 mm/rev.