Page 124 - HOLE_MAKING_CATALOG_INCH_2022_P237-P372

GUNDRILLS Single Flute Gundrill Single Flute Solid Carbide Gundrills USER GUIDE

ISCAR’s gundrill consists of a single-piece carbide head,
Another type of gundrill is made with integral tip and
a streamlined shank and a driver through which coolant
flows to the working end where it is most needed. Chips
carbide driver. These drills are designed for conventional
machines, machining centers and lathes. This style of
are evacuated along the V-shaped external flute. shank, made of solid carbide with either a steel or a
gundrill is available from .035-.630” 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 .035 to .630 11.81 inch
coolant holes. It is made of hardened steel that is
highly resistant to twisting. This cross-section Standard Gundrill Head Sharpening Angles
provides the optimal conditions for twist Subject to the required tolerance, cutting performance
resistance, coolant flow and chip evacuation. and desired chip shape, the following standard sharpening
angles are recommended (shown in figures 1 and 2).
Driver
The driver ensures the connection between 1 Standard sharpening for .035 to .157” drill diameters
the gundrill and the machine tool, (see page 362
for detailed driver information).
Advantages
• Drilling precision of IT7 to IT9 tolerances can be reached 30˚
• Excellent straightness and concentricity 30˚
• Maintains high precision hole center alignment 15˚
• Surface roughness of Ra 16-63µin is easily obtained 30˚ 40˚ 35˚
• Reboring operations are often unnecessary
0.25xD
Carbide Tipped Gundrill Range
D
Drill diameter Max. flute length
.098 to .121 43.30 2 Standard sharpening for .157 to 1.25” drill diameters
.122 to .235 98.42
.236 to .448 118.1
.449 to 1.57 137.8 .012-.019
Overall length=flute length+driver length (see page 365) 12˚
30˚
20˚
12˚
Driver 30˚ 25˚
20˚
0.25xD
D
3 Standard sharpening for 1.25 to 1.57” drill diameters
Shank

20°
Drilling head 25° 12° .012/.02
20°
15° 12° 20°
ISCAR’s advanced gundrill technology provides D/4 ±.002 25°
superior geometric and dimensional quality for Ø Dh5
both deep and shallow drilling. The drills are Note: For special or semi-standard gundrills, special geometries will be
available in the range of .098 to 1.57”. offered to match the application.

360 ISCAR