The high-performance diamond core bit allows you to drill various materials accurately and professionally. The high-quality drill bit has a diamond coating which ensures exceptionally high durability and longevity. Say hello to clean cuts, and goodbye to inconvenient burrs! Even the hardest materials can be drilled safely and efficiently with this core drill. Once the core bit is attached to the arbour insert the pilot or guide drill into the arbour, pushing it in until it goes tight. Most domestic use diamond core cutters will always have a removable guiding drill bit which acts as a pilot hole to guide the core drill.

A core drill should always be used with a power drill, at minimum around 800 watts and at maximum somewhere around 1300 watts. Your chosen drill should also have a variable speed function (somewhere between 100 and 300 rpm) and it must also have a safety clutch! In the majority of domestic cases the largest hole you will need to drill will probably be around 6 inches in diameter through a standard cavity wall which will be around 300mm in depth. For anything up to this size a dry cutting diamond core bit will be more than up to the job.

You can never take it for granted that work hasn’t been done by someone else in this area before and it has not been recorded. Generally, the guide or pilot bit is just used to get you started and keep the actual core bit in position whilst cutting into the surface of the wall. The drill bit itself features carbide “teeth” that surround the circumference of the drill bit. Once rotating, these teeth bite into the surface you’re working on and cut their way through creating the required hole. However, leaving it in will allow you to see when it is about to break through the opposing side of the wall you’re drilling through. More about this and why this is a good thing can be found below. As always at DIY Doctor we advise the use of purpose built tools for DIY use. Safety must always come first. Wear the appropriate safety equipment, gloves, dust masks and eye protection at all times.

For example, smaller holes up to 30mm in diameter can be drilled at up to around 3000 rpm whereas large holes around 400mm should be drilled at speeds as low as 300rpm. With everything assembled it’s time to start drilling your hole. Position the tip of the guide drill on your drilling mark and start the drill slowly, increasing speed slightly until the pilot drill starts biting into the wall.When hiring or buying a core bit always make sure you have the correct size and type of arbor for not only the core bit your are using but also for the type of drill you have e.g. SDS, spline, straight shank etc. If you are able to drill right the way through the wall in one go, the core drill will remove the core at exit. Keep a close eye on your drilling depth and once you are roughly within and inch of breaking through the wall on the other side, decrease any pressure and also speed slightly. Trying to drill more dense objects such as solid concrete will in most cases cause the bit to heat up, wearing it out even faster.