Page 301 - ISCAR(HOLE_MAKING_CATALOG_65)

USER GUIDE
GUNDRILLS

Single Flute Gundrill Single Flute Solid Carbide Gundrills
Iscar's gundrill consists of a single-piece carbide head, Another type of gundrill is made with an integral tip and
a streamlined shank and a driver through which coolant shank, made of solid carbide with either a steel or a
flows to the working end where it is most needed. Chips carbide driver. These drills are designed for conventional
are evacuated along the V-shaped external flute. machines, machining centers and lathes. This style of
gundrill is available from 0.9-16 mm and can be used on
Drilling Head various types of materials. It provides superior rigidity and
The carbide head is tapered on its length to reduce optimal coolant flow rates. As a result of its rigidity, up to
friction. The taper angle depends on the type of material 100% higher feed rate can be reached.
to be drilled. For high precision drilling, the taper should be When using the small diameter drills, it is crucial to
reduced to a minimum. adhere closely to the recommended drilling parameters.
Note that when the head is resharpened, the diameter
of the drill changes, affecting the hole tolerance. Solid Carbide Gundrill Range
(with or without brazed steel driver)
Shank Drill Diameter Max. Flute Length
The cross-section of the shank is V-shaped with 0.9 to 16.00 300 mm
coolant holes. It is made of hardened steel that is
highly resistant to twisting. This cross-section
provides the optimal conditions for twist Standard Gundrill Head Sharpening Angles
Subject to the required tolerance, cutting performance
resistance, coolant flow and chip evacuation.
and desired chip shape, the following standard sharpening
Driver angles are recommended (shown in figures 1 and 2).
The driver ensures the connection between 1 Standard sharpening for 0.9 to 4 mm drill diameters
the gundrill and the machine tool, (see page 301
for detailed driver information).

Advantages
• Drilling precision of IT7 to IT9 tolerances can be reached
• Excellent straightness and concentricity 30˚
• Maintains high precision hole center alignment 30˚
• Surface roughness of R0.4 - R1.6 is easily obtained 15˚
• Reboring operations are often unnecessary 30˚ 40˚ 35˚
Carbide Tipped Gundrill Range 0.25xD

Drill Diameter Max. Flute Length D
2.50 to 3.09 1100
3.10 to 5.99 2500 2 Standard sharpening for 4 to 32 mm drill diameters
6.00 to 11.39 3000
11.40 to 40.00 3500
Overall length=flute length+driver length (see page 303)
12˚ 0.3-0.5
30˚
20˚
12˚
Driver 30˚
20˚ 25˚
0.25xD
D

3 Standard sharpening for 32 to 40 mm drill diameters
Shank

Drilling Head 20°
12° 0,3/0,5
25°
Iscar’s advanced gundrill technology provides 15° 12° 20° 20°
superior geometric and dimensional quality for D/4 ±0,05 25°
both deep and shallow drilling. The drills are Ø Dh5
available in the range of 2.5 to 40 mm. Note: For special or semi-standard gundrills, special geometries will be
offered to match the application.

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