25
DIFFERENCE
IN
RELATIVE LIP HEIGHT
WILL DRILL AN OVERSIZE
HOLE.
UNEVENWEB
THINNING
WEB THINNING
TOO GREAT
Web thinning is recommended for:
1.
restoring chisel edge to the original length after several
regrinds.
2.
larger drills where the machine thrust is limited.
3.
difficult materials.
Lip Clearance Angle
Drill Size (mm)
Angle (°)
Up to 3
18 - 24
3.1 - 6
14 - 18
6.1 - 12
10 - 14
12.1 - 20
8 - 12
Above 20
6 - 10
LIPS UNEQUAL LENGTH
(DIFFERENCE IN RELATIVE
LIP HEIGHT.)
