|
Step 1) |
Position horizontal register at +30° , (half round drills at +20°), vertical register at +12°. Grind until all
wear is removed. |
|
Step 2) |
Position horizontal register at +29°, (half round drills at +19°), vertical register at +20°. Grind to establish
the primary relief width of approximately 5% of the diameter. |
|
Step 3) |
Position horizontal register at -20°, (half round drill at -15°), vertical register at +12°. Grind to establish
the point position width of drill diameter. (Dia./4). |
|
Step 4) |
Position horizontal register at 0°, vertical register at +25°. Grind front clearance until the triangle created
reaches the rear edge of the primary relief. |
|
Step 5) |
For gun drill only. Position horizontal register at -25°, vertical register at -12°. Grind until the triangle
formed reaches the center of the tip "V". |
|
Step 6) |
Remove drill and freehand a periphery chamfer around the radial surface at approximately 20°, stopping just short
of the primary relief. |
