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.

Diamond Drills and Core Bits - Machine Mart Diamond Drills and Core Bits - Machine Mart

In general, a corded drill is the best to go for as it will produce power at a more constant rate, but if funds are available, the more expensive and higher quality cordless drills (minimum 24v) from brands such as DeWalt, Makita, Milwaukee etc should provide more than enough grunt. 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. Before you start your drilling you should always make sure there are no cables or pipes hidden in the wall at the spot you intend to drill your hole. Again, as we have also touched on above, there are several different types of core bit available and depending on the object you are drilling through and the size of hole you need to create will ultimately depend on what type of core drill your should use. Carbide Core Drill Bits Due to the amount of heat created during the drilling process it is necessary to keep diamond core bits as cool as possible to prevent unnecessary damage to the cutting teeth to a minimum. If the surface of the cutting teeth are subjected to too much heat the metal encasing them melts covering the diamonds and reducing cutting efficiency. If this happens the drill bit then needs to be “redressed” to expose the diamonds once more.At this point you will only have around half an inch or so to drill through so take your time and once done you will be left with a nice neat and clean hole. For the neatest cut and finish to your hole it is advisable to then finish the hole from the other side. This guarantees both a neat entry and exit hole. 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.

Core Drill Bits Sets | Diamond Tools | Sydney Tools Diamond Core Drill Bits Sets | Diamond Tools | Sydney Tools

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.There are many core drill sizes and generally each size is manufactured to represent the size of a commonly used pipe, cable or duct so that once the hole is drilled, the object in question passes through with ease.

TCT Core Drill Bit 50mm | Toolstation

If you are able to drill right the way through the wall in one go, the core drill will remove the core at exit. 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. 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. As well as wearing the drill bit out much faster, the hammer action also creates a lot of vibration whilst drilling often leading to the hole ending up larger than intended.

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. 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. Although it is not recommended, many use hammer action with these drill bits to increase their cutting speed and ability. This will ultimately wear the core bit out much faster, but as they are generally cheap this is not often seen as a major concern. With the drill held straight and true, keep drilling, stopping regularly and withdrawing the bit from the hole to allow it to cool down. When withdrawing a core bit from a hole ensure that it is still rotating. Essentially the speed that you drill at will be dictated to you by the size of hole you are drilling. As a very general rule of thumb, the larger the hole you are drilling and the denser the material you are drilling through, the slower the speed you should drill at.

Erbauer Diamond Core Drill Bit 52mm - Screwfix Erbauer Diamond Core Drill Bit 52mm - Screwfix

If in any doubt always refer to the manufacturers instructions for your particular power drill and also for the core bit you are using. In both cases, each set of instructions should state the correct drilling speed you should be using. Preparing for Drilling Holes Using a Core Drill

If however the depth of the hole is longer than the drill bit you will need to withdraw the core bit when you hit a depth of about 125-130mm and chop out the core with a hammer and bolster, or in some cases you can lever it out. Corded power drill with safety clutch and variable speed ideal for use with a core drill How Fast Should you Drill When Using Core Bits? 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. 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.