Chisel Point Inconcentricity

UT tolerance (ø0.3mm) : 0.01mm or less

Hole Qualities

A:Poor registration accuracy

Distortion through the hole will occur from the upper surface.
Furthermore, it will also cause the drill bit to deflect further worsening registration accuracy.

B:Large hole sizes

In a general, drill bits centre around the chisel point.
Therefore, where the chisel point is excentricity - the centre revolution has a gap - so the hole size becomes larger.

Countermeasure (Setting of drill point)

1.Use suitable drill well for drill specification and diameter.

List of drill well

V-type

2.Adjust the amount of drill protrusion from drill well.

*Ideal amount extending from the drill well is usually very small, however when re-pointing UC type drills, make sure that the entire head protrudes from the drill well.
(As it the margin part maybe chipped, avoid using this part to rest the drill in the drill well.)

3.Adjust the universal joint (Correcting runout)