Why diamond core bit segment broken during coring

Sometimes in the world of concrete core drilling we face the frustration of loosing a core bit segment or two while drilling, more times than not it’s that urgent job that must be done NOW.

So let’s take a look at WHY this might happen. This is written in regards to wet series concrete diamond core drill bits

1. Manufacturing Fault

One possible cause could be that a core bit segment might not have been brazed or laser welded on properly. If this is the case, the diamond core bit segment will more than likely come off within the first hole. Usually in the first 50mm depth of cut.

To determine if this is the case, where the core bit segment is missing from the barrel, it will look and feel smooth. You will notice that the diamond drill segment is also rather smooth on the surface that was welded to the core barrel. This is most likely with brazed core bits.

Don’t assume that just because a segment has come off drilling your first hole that it is a manufacturers fault. It can just be unlucky that it was your first hole and something within the slab or material has caused it to happen, which leads to the next possible causes.

2. Debris and loose particles.

More often than not, a diamond core bit segment comes off or breaks because of debris within the hole you are drilling. This could be a piece of reinforced bar that has somehow become lodged between the segments while drilling. It could be something else like a piece of stone thats been dislodged.

Sometimes it is hard to determine exactly what caused it to break off in this instance. If the diamond core drill bit has been used numerous times and then a diamond core bit segment comes off while drilling into the material it is safe to say that it is not a manufacturing fault.

3. User Error

Yes, it could actually be your fault! Have you got water flow while drilling? Are you using the correct drill type and speed for the diameter size? Are you applying too little pressure to cause vibration? If your drilling through a concrete slab, are you pulling up before it hits the fill or debris beneath? Do you feed enough water?

There are many reasons why diamond core bit segments can break or snap off. The above were just a few examples which came to mind while writing this.