Challenger™ TCI Roller Bearing Features

For sizes 14 ¾” and larger

Advanced Cutting Structure

Challenger™ tungsten carbide insert (TCI) cutting structures are designed to be durable, while maintaining the highest efficiency in rock destruction. Insert row placement and insert spacing are determined using Varel’s proprietary algorithms designed to reduce wear, prevent tracking, promote efficient drilling and ensure uniform loading across the bit face.

Gage Protection

Advanced gage protection is standard on all Challenger TCI bits. Semi-round top (SRT) tungsten carbide inserts on the back row aid in cutting the wall of the hole. These resist wear better than flat-topped inserts.

Diamond Enhanced Back Row (D feature)*

One third of the carbide back row inserts is replaced with polycrystalline diamond (PCD)-capped inserts to increase gage holding in abrasive applications.

Diamond EnhancedGage and Back Rows (DD feature)**

One third of the back row and all gage inserts utilize PCD-capped inserts to maximize gage holding.

Fully Diamond Enhanced Cutting Structure (DDD feature)*

All inserts are PCD-capped to extend bit life in the most abrasive applications.

Shirttail Contouring

Extensive shirttail contouring and clearance from the wall of the hole ensures that fine cuttings are carried away from the seal area, providing longer seal life.

Center Jet Nozzle (J feature)**

A fourth interchangeable jet is installed in the center of the bit to reduce bit balling or provide extra flow capacity. (Available in 8 3/8" and larger bits only)

Shale Diverting Insert/Shale Groove - Standard

Challenger bits feature an innovative, stepped shale burn insert. This stepped design is more effective in diverting cuttings away from the seal, prolonging seal life.