Drilling holes in composites

Care must be taken with drilling to avoid the creation of additional damage around the hole, especially for laminated composites where damage can be introduced in the form of delaminations and cracking.

Preparation and tool selection for drilling are dependent upon the composite system. Drill material, drill geometry, drill rpm settings, feed control rates and the provision of a firm backup support while drilling all require attention.

Before selecting the drill type and drilling parameters, the material type and lay-up should be known to allow the correct drill type to be selected. Specialised tungsten carbide or diamond tipped drill bits are recommended, especially for drilling carbon composites.

Suitable dust extraction is required not only for health and safety reasons but also to prevent conductive and abrasive carbon dust infiltrating any electrical circuits or machinery.