China Drag Bits Hlyd116

Drag Bits (three wings or four wings), or Blade Bit
Material quality: Wing-tungsten carbide + body-alloy steel
Diameter: 76mm - 445mm
The thread parts is integral with the body
All with international standard API reg threads.
Drag bits have a shearing action and cut rapidly in sands, clays and some soft rock formations.
Most drilling is done using the Drag bit (especially in clay and sands).
However, it does not work well in coarse gravel or hard-rock formations.
Drag bits have short blades, each forged with a cutting edge and faced with tungsten carbide tips.
A blade bit is a drag bit in which the blades can be replaced.
Whenever possible, drag bits should be used to drill pilot holes because they produce cuttings which are easiest to log.