Exactaform Logo

Articles by Neil McKinnell

Side-by-side comparison of a matte black CVD diamond-coated drill and a polished carbide brazed PCD drill on a dark surface for composite drilling applications.
  • Diamond Coated Drills
  • Aero-CARB

Diamond-Coated vs PCD Drills for Composite Drilling

Diamond-coated drills suit low-to-mid volume composite drilling, where you need more wear resistance than carbide without committing to a bespoke tool. PCD-tipped drills offer the highest capability in higher-volume production, where their longer tool life and process stability can be measured. The right choice should always come down to the most cost-effective solution for the job, taking into account the volume of work, the projected cost per hole, and availability meeting demand.

Extreme macro photograph of a solid carbide twist drill bit with a matte black CVD diamond coating on a dark charcoal background.
  • Diamond Coated Drills
  • Aero-CARB

How CVD Diamond Coating Is Applied to Carbide Drills

CVD (chemical vapour deposition) diamond coating is applied by growing a dense layer of diamond directly onto a finished carbide drill in a high-temperature reactor. The diamond bonds to the carbide and forms a hard, wear-resistant barrier between the tool and the abrasive material it cuts, so the drill holds its cutting edge in CFRP, graphite and aluminium-silicon far longer than uncoated and conventional coated carbide. It is not the same as PCD, where a diamond tip is brazed onto a tool body; here the diamond is grown as a layer of coating.