Multiple blades (6 or 3) allows better centralization and hole tracking especially in horizontal underreaming, mill sectioning or cutting casing.
Air, air mist, water or drilling circulation may be used.
Normal or reverse circulation.
Can cut up or down.
Can cut longer intervals due to longer blade widths.
Drill and underream simultaneously.
Mill and underream simultaneously.
Various tipping and materials available including long life tungsten carbide rollers, tungsten carbide disc cutters, pdc (polycrystalline diamond compact) disc cutters and hardfacing.
Circulation used more efficiently to open tool and clean hole.
Special alloy steel with high hardness and impact strength.
Various closed and open diameter combinations available.
Harvest Tool Company has over 12 years of record underreams and hole enlargement.