PCD(TSP) core bits are similar to surface-set diamond bits in that they are set with a single layer of cutters mounted on the face of the bit in a pre-determined pattern. Instead of natural drill diamond however, the cutting media used on geotechnical bits are synthetic polycrystalline diamond elements. These elements are composed of micron-sized particles of synthetic diamond that have been formed into various geometric shapes.

Like surface-set diamond bits, geotechnical bit crowns consist of a tough wear resistant matrix body that as a minimum includes natural diamond gauge protection setting. In most cases, the gauge protection setting is augmented with seismic grade tungsten-carbide pads and/or polycrystalline diamond elements.

Shear is the mechanism by which geotechnical bits cut the formation being drilled. In softer formations, these bits are capable of very high rates of penetration when compared to surface-set diamond bits due largely to their high degree of cutter exposure.

 TSP Core Bits are ideal for geotechnical drilling applications. They are suited for soft to medium hard formations, such as clay, shale, sandstone, limestone, marble, basalt, etc

Properties

Special-shaped PCD  are embedded in the matrix as cutting media. High penetration rates are common due to maximum setting exposure of the PCD providing an aggressive cutting face. 

 
Manufactured with a very erosion resistant matrix. Inside and outside gauge diameter integrity is maintained with a combination of natural diamonds and PCD pins. 
 
As PCD is very wear resistant material, PCD core bits have a long bit life.

Three types of PCD Core Bits

TSP(Geo cube set) Type, Spicula Type, Cyclinder Type, like the following pictures show.