Quick release drill bit for down-hole drills

Radon gas home/building mitigation apparatus and method

Rock drilling apparatus

Rotary table and kelly guard

Rotatable drill string having a torsionally elastic shaft drivin

Self-drilling dowel assembly with an annular drill bit

Self-drilling dowel with drill head

Self-drilling thermal bolt

Self-sinking, axial passage foundation pile and method

Service module for hostile environment

System and method for installing production casings

System and method for installing production casings

Telescoping torque transmission apparatus

Tension shock absorber device

Unitary drill bit and roof bolt

Vertically adjustable pipe racking apparatus

Vibration isolator

Well jar

Well jar