Hammond recommended geometry for various materials
| DRILL DIA. | PRIMARY LAND | CHAMFER AT 20° |
|---|---|---|
| Ø 3,0 to 12,0 | 0,4 – 0,6 | 0,4 – 0,6 |
| Ø 12,0 to 25,0 | 0,6 – 0,8 | 0,6 – 0,8 |
| Ø 25,0 to 32,0 | 0,8 – 1,2 | 0,8 – 1,2 |
| FACET DESCRIPTION |
NG4 ALUMINIUM (Order code B) |
NG13 CAST IRON (Order code E) |
NG80 FLAT BOTTOM (Order code G) |
||||
|---|---|---|---|---|---|---|---|
| HORIZONTAL | VERTICAL | HORIZONTAL | VERTICAL | HORIZONTAL | VERTICAL | ||
| A | OUTER PRIMARY | +15° | +15° | +40° | +12° | +1° | +12° |
| B | OUTER SECONDARY | +14,5° | +20° | +39,5° | +25° | +1° | +20° |
| C | INNER RELIEF | -20° | +15° | -20° | +12° | – | – |
| D | FRONT CLEARANCE | 0° | +25° | 0° | +35° | – | – |
| E | OIL DUB-OFF | -25° | -15° | -25° | -12° | 25° | -12° |
| POINT POSITION | D/4 | D/4 | D/2 | ||||
| FACET DESCRIPTION |
NG82 SUPER ALLOYS (Order code H) |
NG86 WOOD GRIND (Order code K) |
NG90 MALLEABLE MATL (Order code L) |
||||
|---|---|---|---|---|---|---|---|
| HORIZONTAL | VERTICAL | HORIZONTAL | VERTICAL | HORIZONTAL | VERTICAL | ||
| A | OUTER PRIMARY | +42° | +14° | +30° | +20° | +20° | +20° |
| B | OUTER SECONDARY | +41,5° | +25° | – | – | – | – |
| C | INNER RELIEF | -17° | +14° | -20° | +20° | -20° | +20° |
| D | FRONT CLEARANCE | 0° | +30° | 0° | +30° | 0° | +25° |
| E | OIL DUB-OFF | -22° | -15° | -25° | -15° | -25° | -15° |
| POINT POSITION | D/5 | D/3,5 | D/3,5 | ||||