Drills also need a pilot hole (except 22 and 28mm) to locate the bit at the start of drilling and steer it through the correct line. The pilot hole can be drilled concurrently with the pilot drill fitted to the adaptor, or it can be pre-drilled, (preferrable if you are not sure of what may be in the wall!) Guide drills have a tapered fit which locates in the adaptor and protrudes right through the core drill beyond the core bit (see photo). They can be easily pushed out with a drift key.

Lengths shown are extension lengths and exclude the adaptor fittings which insert into the drill and core bit.

 Starting Kit: If you don't have any fittings you will need as a starting point:

• Adaptor or extended adaptor of your choice
• Guide drill (except on 22 and 28mm core bits)
• Drift key to remove guide drill.