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 are evacuated along the V-shaped external flute.

1. The Drilling Head
The carbide head is tapered on its length to reduce friction. The taper angle depends on the type of material to be drilled. For high precision drilling, the taper should be reduced to a minimum. Note that when the head is resharpened, the diameter of the drill changes, affecting the hole tolerance.

2. The 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 provides the optimal conditions for twist resistance, coolant flow and chip evacuation.

3. The Driver
The driver ensures the connection between the gundrill and the machine tool. ISCAR’s advanced gundrill technology provides superior geometric and dimensional quality for both deep and shallow drilling. The drills are available in the range of 2.5 to 32 mm in 0.1 mm increment diameters. Larger diameters, between 32 and 40 mm, are available upon request. In addition, any other drilling head configuration or coated drilling head can be produced upon request.

• Drilling precision of IT7 to IT9 tolerances can be reached.
• Excellent straightness and concentricity.
• Maintains high precision hole center alignment.
• S urface roughness of R0.4 - R1.6 is easily obtained.
• R eboring operations are often unnecessary.

Drill Diameter	Max Flute Length
2.50 to 3.09	1100
3.10 to 5.99	2500
6.00 to 11.39	2800
11.40 to 23.60	3100
23.61 to 33.00	2700
33.01 to 35.00	2500
35.01 to 40.00	2200

Overall length=flute length+driver length