Application notes diamond core bits
Cooling is a topic of much debate in the diamond core bit field. Drilling and sawing service providers consider water to be indispensable during drilling. It helps to cool the drilling process and to dissipate the material removed as sludge. This achieves both short drilling times and a long service life of the core bit.
But home owners and construction site managers often want to do without using water. After all, it soils nearly finished, or inhabited rooms. On top of this, water accumulates in intermediate ceilings and can thus cause a problem with damp.
Heller offers only diamond core bits in which the diamond segments are welded using laser technology. Temperatures of up to 1000 °C can be transferred without any damage to the core. The break out values are thus minimised compared with rival products thanks to our special laser welding technique. This means that Heller diamond core bits can be used in masonry and screed in dry state. In this case, you must use a dust rotor to take up the dust from drilling and avoid clogging and jamming of the bit. In concrete and reinforced concrete water is indispensable as a coolant to allow the core to achieve sustainably reliable results.
Correct fastening of the core drilling stand:
We recommend running drilling motors in a core drilling stand to make sure that the core bit is always fed to the drill hole in a straight line. This helps to achieve a smoother drilling process. At the same time, the core bit is protected against damage and the precision of the bore is ensured.
Pay attention to correct anchoring. The most commonly used anchoring type is the anchoring dowel and the thread rod with wing nut. For smaller core drill holes, clamping with a quick release column is also suitable. If the substrate is flat, the drill stand can also be attached using a vacuum. Please also note the operating manual for your core drilling stand at all times.
In case of smaller bore diameters and softer materials, freehand use is also possible. However, it is absolutely essential to feed the bit smoothly in this case.
• When selecting the diamond core bit, make sure you choose the right coupling. 1/2" couplings are suitable for bores with a diameter of up to 131 mm. Core bits with a 1 1/4" coupling are available for applications above 51 mm
• Always select a low contact pressure. Only turn the guide wheel on the core drill stand slightly. The core bit will work its own way into the material. Excessive pressure can cause the diamonds to break. Temporarily interrupting the contact pressure will improve the supply of cooling water and allow bore sludge to escape
• Diamond core bits generally need a circumferential speed of 2 to 3.5 m/s. Try to set the speed as precisely as possible
• When drilling through ceilings, it is a good idea to secure a plastic tray below the ceiling to catch the core when it falls out. This also prevents water entering the floor below. The best way to support the tray is to use steel supports
• A dust and water vacuum offers an optimum approach to taking up water. In this case, it is often possible to leave the furniture in the room. When drilling in walls, you can catch the water that escapes with a foil and collect it in a bucket
• If you are drilling in multiple layer ceiling structures with interior insulation and building foil, it is a good idea to drill through to the insulation using a larger diameter first, and then mask the circumference of the bore with foil to avoid water entering the insulation. You can now continue to drill at the required diameter through the complete ceiling.