Boart Longyear

Casing Bits

Boart Longyear offers a large selection of casing bit to serve a wide variety of ground conditions. Casing bits are designed for rotary-percussive or rotation only drilling based on the tungsten carbide inserts utilized as well as the geometry of the bit. In addition to our standard offering, we offer customized tools for unique drilling applications.

Construction
Casing bit bodies are constructed of high strength quenched and tempered steel. The high quality tungsten carbide inserts are induction brazed into the steel bodies ensuring a secure fit without overheating issues associated with flame brazing. Strict machining control of the carbide seats prevent premature loss of carbide inserts.

Gauge Protection
Boart Longyear offers tungsten carbide gauge protection on casing bits. Gauge protection will prevent excessive wear on the outer diameter of the bit in abrasive grounds. Additionally, in unconsolidated ground conditions where the ground is caving in on the drill string the gauge protection will assist in freeing the bit and casing by providing another cutting surface.

Shrink Fit Carbides
We can offer, on request, shrink fitting installation of all hemispherical, ballistic, and two-step tungsten carbide inserts instead of the standard induction brazing. This very precise construction method is often utilized when drilling in extremely hard ground conditions and provides both increased button retention and longer overall life.

Advantages
• Computer controlled inductive brazing of tungsten carbide inserts provides superior process control and prevents overheating common with flame brazing.
• High grade body construction with quenched and tempered steels.
• Optional tungsten carbide gauge protection available to assist in unconsolidated grounds and increase life in abrasive conditions.
• Specialized designs for unique drilling situations such as drilling through reinforced concrete and drilling without inner bits.