1. Matrix Body PDC Bits"Matrix" is a very hard, rather brittle composite material comprising tungsten carbide grains metallurgically bonded with a
softer, tougher, metallic binder. Matrix is desirable as a bit material, because its hardness is resistant to abrasion and
erosion. lt is capable of withstanding relatively high compressive loads, but, compared with steel, has low resistance to impact loading. Matrix is relatively heterogeneous, because it is a composite material. Because the size and placement of the particles of tungsten carbide it contains vary (by both design and circumstances, its physical properties are slightly less predictable than steel. Matrix-body PDC bits are commonly preferred over steel-body bits for environments in which body erosion is likely to cause a bit to fail. For diamond-impregnated bits, only matrix-body construction can be used.
2. Steel Body PDC Bits
Steel is the opposite of matrix. It can of withstanding high impact loads, but is softer and lacks protective features. The
strength and ductility of steel give steel-bit bodies high impact resistance. Steel bodies are considerably stronger than matrix bodies. A beneficial feature of steel bits is that they can easily be rebuilt a number of times because worn on damaged cutters can be replaced rather easily. This is a particular advantage for operators in low-cost drilling environments.