Technique for drilling straight bore holes in the earth

Telescopable boring rod mechanism

Telescopic bar of drill rig

Telescopically extensible drill

Telescoping casing joint for landing a casting string in a well

Thread joint percussive drilling equipment

Thread retention for an earth boring device

Threaded spacer

Tilting bit crown for earth-boring drills

Tool for forming a hole for a fastening element

Tool joint stress relief groove

Tool module connector for use in directional drilling

Torque converter for use when drilling with a rotating drill...

Torque transmitting device for rotary drill bits

Tube auger sections

Tubular drill string member with contoured circumferential surfa

Twist drill

Twist drill bit for rock drilling

Two piece down hole drill chuck