| Core Bit Size |
Rec. Min RPM |
Rec. RPM |
Rec. Max RPM |
| 1 Inch |
2380 |
3180 |
3980 |
| 2 Inch |
1190 |
1590 |
1990 |
| 3 Inch |
790 |
1060 |
1320 |
| 4 Inch |
590 |
790 |
990 |
| 5 Inch |
477 |
636 |
790 |
| 6 Inch |
390 |
560 |
660 |
| 7 Inch |
340 |
450 |
560 |
| 8 Inch |
290 |
390 |
500 |
| 9 Inch |
260 |
350 |
490 |
| 10 Inch |
230 |
310 |
400 |
| 12 Inch |
200 |
260 |
330 |
| 14 Inch |
170 |
220 |
280 |
| 16 Inch |
150 |
200 |
250 |
How to find the right RPM
Start off with the recommended RPM on the table you see above. From there, you will need to adjust to different variables. Different types of aggregate will need different speed, pressure, water, etc. A good operator will be able to feel the right speed and pressure to use. It takes skill and experience to tell.
If the drilling speed is too high, the bit will glaze over the diamonds preventing it from drilling.
If its too low, the drilling will take far too long.
Adjust accordingly.
If you do find the bit is glazed over, but there is still segment left, take the bit out of the hole and drill into some soft, abrasive cinder block to open up new diamonds.
For drilling through rebar, do not apply additional pressure. Apply the same amount of of pressure and do not force the bit into the drill.
Any questions or comments please feel free to call us at 800-618-5000.
