Not too long ago, one of our customers had taken on a project that involved drilling on a hydroelectric dam to verify the condition of the structure and to inject concrete into the foundations. This kind of project is pretty common in the geotechnical world and can involve other structures such as overpasses.
Drilling was supposed to easy as not much drilling depth was required. What the customer had not expected though, was that the concrete in the dam was reinforced with steel bars. He was using thin walled core bits and he was going through them at a rapid pace. His budget was suffering as a result. In another case, a customer with a similar project had followed the suggestion of the project manager and opted for bull-nosed bit.
These options may work with some measure of success but they are not optimal choices. The thin-walled core bit does not have enough diamond matrix height nor does it allow for efficient removal of cuttings. The bull nosed bit will eat away at too much concrete. More importantly, bull nosed bits are very costly due to the manually set natural diamonds used in the manufacture of these tools.
Better results in concrete at a reasonable price are possible by choosing a mid-range thin kerf diamond bit such as the type used in a wireline system, e.g. Primo 6. This choice of bit will cut a thinner kerf of the concrete, leaving a larger core sample that can be discarded if not needed. A Primo 6 will drill faster than a bull nosed bit, has a good diamond matrix height and allows for optimal flushing and cooling of the bit face works. Adding a drilling additive such as Torqueless will extend the life of the bit even more.
If the amount of steel you need to drill through is substantial, then opt for the lowest number in the series, such as the Shark. For additional information or advice on specific drilling conditions, don’t hesitate to contact our tech support team.