Diamond coated parabolic drill for composites

A diamond coated parabolic drill for drilling both carbon fibre and carbon graphite materials overcomes typical problems associated with delaminating, flaking, splintering and whiskering, caused by the highly abrasive nature of the material. The design of the drill also reduces thrust forces, gives more manageable chip formation, improved centring and faster penetration rates. The profile of the Parabolic Flute Form Drill improves chip flow, swarf evacuation and resistance to wear and abrasion through a combination of tool geometry and the multi-layer nano-crystalline, six micron thick diamond coating. The drill has a 30 per cent web thickness, compared to 12 to 15 per cent conventionally, adding both strength and rigidity. Under cutting conditions, the flute re-distributes mass to the outer cross-sectional area of the tool’s construction and due to the greater helix angle of 36 to 40 deg, instead of the normal 28 to 32 deg as standard tools, a significant increase in the shearing action of the cut is achieved.