Page 115 - HOLE MAKING CATALOG p185-310

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
The cross-section of the shank is V-shaped with Drill Diameter Max. Flute Length
coolant holes. It is made of hardened steel that is
highly resistant to twisting. This cross-section 0.9 to 16.00 300 mm
provides the optimal conditions for twist
resistance, coolant flow and chip evacuation. Standard Gundrill Head Sharpening Angles
Subject to the required tolerance, cutting performance
Driver and desired chip shape, the following standard sharpening
The driver ensures the connection between angles are recommended (shown in figures 1 and 2).
the gundrill and the machine tool, (see page 301
for detailed driver information). 1 Standard sharpening for 0.9 to 4 mm drill diameters

Advantages 30˚
• Drilling precision of IT7 to IT9 tolerances can be reached 30˚
• Excellent straightness and concentricity
• Maintains high precision hole center alignment 15˚
• Surface roughness of R0.4 - R1.6 is easily obtained 30˚ 40˚ 35˚
• Reboring operations are often unnecessary
0.25xD
Carbide Tipped Gundrill Range
D
Drill Diameter Max. Flute Length
2 Standard sharpening for 4 to 32 mm drill diameters
2.50 to 3.09 1100

3.10 to 5.99 2500

6.00 to 11.39 3000

11.40 to 40.00 3500

Overall length=flute length+driver length (see page 303) 0.3-0.5

12˚
30˚

20˚

Driver 12˚ 30˚
20˚ 25˚

0.25xD
D

3 Standard sharpening for 32 to 40 mm drill diameters

Shank

Drilling Head 20°

Iscar’s advanced gundrill technology provides 25° 12° 0,3/0,5
superior geometric and dimensional quality for 15° 12° 20° 20°
both deep and shallow drilling. The drills are
available in the range of 2.5 to 40 mm. 25°

D/4 ±0,05

Ø Dh5

Note: For special or semi-standard gundrills, special geometries will be

offered to match the application.

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