Silverline 199883 TCT Core Drill Bit 110 mm

Product Information

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.

When using dry cutting bits it is essential that they are kept as cool as possible. To do this they should be used in short bursts and the whole bit should be regularly withdrawn from the hole and exposed to the air to disperse any heat. Despite this, dry cutting diamond core bits don’t have to be used dry you can also use them wet. 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. 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 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. 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.With the drilling point clearly marked on the wall, next setup your core bit and drill. Screw the arbour into the end of the core bit until it’s pinch tight. 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. 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. 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. 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.

There are a few different types of core bit and the best one to use will very much depend on the size and depth of hole you’re drilling and the type of material you are drilling through. With the above in mind, dry cutting diamond core bits are generally used when working indoors, whereas wet cutting bits are used externally.

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Diamond core drill and correct sized arbour What Type of Power Drill do you Need for Core Drilling? Drilling a 6mm hole in the wrong place can easily be rectified, but trying to fill in a 4 inch hole is not an easy job at all.

Unlike carbide drill bits, the teeth on a diamond core bit features diamonds that are embedded in the teeth themselves. As diamonds are extremely hard they grind their way through the surface you’re working on creating a sharp and clean cut. 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. 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!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. 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. 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. 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. If you are able to drill right the way through the wall in one go, the core drill will remove the core at exit.