Page 297 - Hartner
P. 297
Precision
Alignment accuracy
Because brazed single-fluted gun drills always have the preci- 0,06
sion carbide head brazed onto a flexible tube, the tool achieves
very accurate aligned holes remaining unaffected by possible 0,05
concentricity errors. However, extreme material fluctuations
and other influencing factors can impair the alignment accu-
racy. 0,04
Alignment in mm 0,03
0,02
0,01
250 500 750 1000
Drilling depth in mm
Deviation from concentricity
When a hole is produced with for example, a commercial twist stationary workpiece - rotating tool
drill, the quality of the point grind affects the concentricity of anti-clockwise rotating workpiece -
the hole. An imbalance of forces is created at the cutting edges. 1,0 rotating tool
With gun drills, these cutting forces are absorbed by the sup-
porting strips, resulting in excellent concentricity.
0,8
Deviation in mm 0,6
0,4
0,2
250 500 750 1000
Drilling depth in mm
291
04_TLB.indb 291 28.11.11 11:07
