Patented tungsten carbide micro shields are brazed into shallow receptacles to provide the ultimate in shirttail tip protection.


Hard Shell Cones

 Provide maximum durability for any application. Hardfacing is applied in the grooves of the cones to prevent wear and erosion of the cone steel improving cutting structure life.

Hard Shell Cones

Interstitial Inserts

Abrasive formations wear the cone nose away quickly, but with these small tungsten carbide inserts, the TCI cutting structure is protected, eliminating cone wear.

Interstitial Inserts

Shirttail Hardfacing

A generous application of tungsten carbide hardfacing is applied to the shirttail lower and leading edges to provide seal protection.

Motor Hardfacing

Shirttail TCIs

Tungsten carbide inserts are placed along the leading edge of the shirttail providing wear resistance in all applications.

Shirttail Inserts


A shirttail feature that provides a return path for cuttings to flow up the side of the head and into the annulus reducing recirculation of cuttings on bottom and improving ROP through enhanced chip removal.



Shirttail pattern allows drilled cuttings to be removed from the hole more effectively than with standard bit shirttails. This improves penetration rates and reduces regrinding, preventing wear to the cutters and shirttails. The result is a faster drilling bit with longer life, which dramatically lowers total drilling costs.


Vented Cones (> 9” only)

Standard in all D-Force™ / Ridgeback® series bits 9" and larger in diameter, vented cones allow a continuous air flow throughout the bearing to provide better cooling and cleaning.

Vented Cones


For specifications, application solutions, and Feature availability please contact your local Varel Mining and Industrial representative.