-Two speeds: 375 and 750 rpm.

-15 amp motor.

-Shear pin protection protects gears and motor.

-Built-in water swivel.

Diamond coring motors are used with Vac-U-Rig® and Dymorig diamond core rigs to drill holes into reinforced concrete. This 15 amp model provides core drilling power where 20 amp service is unavailable. This unit has a 375 rpm or 750 rpm operating speed. The 4090 uses a shear pin to protect gears and motor against overload. Shear pins are easily replaced and extra pins are included with the unit. This unit will handle core bits from 2-1/2 in. to 8 in. in diameter.