Page 666 - Iscar

USER GUIDE
GUNDRILLS Single Flute Gundrill Carbide Tipped

Gundrill Range
ISCAR's gundrill consists of a single piece carbide head,
a streamlined shank and a driver through which coolant
flows to the working end where it is most needed. Chips
1100
2.50 to 3.09
are evacuated along the V-shaped external flute. Drill Diameter Max. Flute Length
3.10 to 5.99 2500
Drilling Head 6.00 to 11.39 3000
The carbide head is tapered on its length to reduce 11.40 to 40.00 3500
friction. The taper angle depends on the type of material Overall length=flute length+driver length (see page 666)
to be drilled. For high precision drilling, the taper should
be reduced to a minimum. Driver
Note that when the head is resharpened, the diameter
of the drill changes, affecting the hole tolerance.

Shank
The cross-section of the shank is V-shaped with
coolant holes. It is made of hardened steel that is
highly resistant to twisting. This cross-section Shank
provides the optimal conditions for twist resistance,
coolant flow and chip evacuation.
Driver
The driver ensures the connection between
the gundrill and the machine tool, (see page 664
for detailed driver information).
Drilling Head
Advantages
• Drilling precision of IT7 to IT9 tolerances can be reached ISCAR’s advanced gundrill technology provides
• Excellent straightness and concentricity superior geometric and dimensional quality
• Maintains high precision hole center alignment for both deep and shallow drilling.
• Surface roughness of R0.4 - R1.6 is easily obtained The drills are available in the range of 2.5 to 40 mm.
• Reboring operations are often unnecessary

Single Flute Solid Carbide Gundrills

Another type of gundrill is made with integral tip and Solid Carbide Gundrill Range
shank, made of solid carbide with either a steel or a (with or without brazed steel driver)
carbide driver. These drills are designed for conventional Drill Diameter Max. Flute Length
machines, machining centers and lathes. This style 0.9 to 16.00 300 mm
of gundrill is available from 0.9-16 mm and can be
used on various types of materials. It provides superior
rigidity and optimal coolant flow rates. As a result of its Standard Gundrill Head Sharpening Angles
rigidity, up to 100% higher feed rate can be reached. Subject to the required tolerance, cutting performance
When using the small diameter drills, it is crucial to and desired chip shape, the following standard sharpening
adhere closely to the recommended drilling parameters. angles are recommended (shown in figures 1 and 2).

0.3-0.5
12˚
30˚ 30˚
30˚ 20˚
15˚ 12˚ 20°
40˚ 30˚
30˚ 35˚ 20˚ 25˚ 12° 0,3/0,5
25°
15° 12° 20° 20°
0.25xD 0.25xD 25°
D D/4 ±0,05
D
1 2 3 Ø Dh5
Standard sharpening for 0.9 Standard sharpening for 4 to Standard sharpening for 32
to 4 mm drill diameters 32 mm drill diameters to 40 mm drill diameters
Note: For special or semi-standard gundrills, special geometries will be offered to match the application.

662 ISCAR