Page 288 - Hartner

Two-fluted gun drills with solid carbide head Z 80

suitable for cast iron, aluminium and short-chipping nonferrous metals,
from Ø 6.0 - 27.0 mm, max. total length 1000 mm

To ask for or to order Hartner two-fluted gun drills Z 80 with solid carbide head especially suited to your application,
please complete the fax inquiry.

M
MolyGlide
For certain materials a coating is required, as the successful application of gun drills with a bright surface finish cannot be guaranteed. For chilled cast iron and Al
cast alloys with a Si-content above 10% we recommend our MolyGlide-coating. However, two-fluted gun drills can only be coated with MolyGlide up to an ove-
rall length of maximum 500 mm due to the technical production process.

The main advantage of two-fluted gun drills compared to quence of a drill design with two cutting edges. As the cutting
single-fluted gun drills is the substantially higher feed rate that edges are positioned opposite each other, there is less of a
can be applied during the production of the hole. This is due to smoothing effect and less support in comparison to a single-
the design of the two-fluted gun drill, it has two cutting edges fluted gun drill. For drilling depths ≤ 10 x D we recommend our
and two flutes. Holes can therefore be produced considerably TS Drill TS 150 GG, available ex stock and more cost-effective
faster. However, this increase in machining speed is combined for these drilling depths than brazed gun drills. In addition, TS
with a reduction in hole accuracy. This is also a direct conse- 150 GG does not require a pilot hole in most applications.

The dimensions required to calculate the length
for conventional machine tools
* max. flute length per tool
40 x D, for larger drilling depths apply two tools.
(i.e. Ø 10 x 450 and Ø 9.95 x 850 mm)
head length
driver
d 1h5

re-grind min. distance
1,5 x D drilling depth 3 x D driver length
flute length *
total length

Standard point grinds (special point grinds available) Special point grinds, e.g.:

Point grind G Point grind A
for machining for machining Aluminium cast materials
cast iron aluminium
28° 10° 0,5 +0,3 20° 10°

0,5 +0,3
60°
60°
120° 140° R
130 o
D D 130 o

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