Diamond drill bits that come in packs of 30 are cylindrical. The available sizes are limited to 1mm, 2mm, and 3mm. They don’t have a pointy tip. Their depth of cut is shallow. You will need to hold the tool at an angle to get the hole started. Once the hole is started, you can go vertical upright. Twisted diamond drill bits come in different packs, mixed or otherwise. Available sizes are 1mm, 1.5mm, 2.0mm, 2.5mm. Twisted diamond drill bits have a longer depth of cuts, they have the 120-degree standard pointy tip. You can start upright. Twisted diamond drill bits are a bit more expensive than cylindrical ones.
Our diamond hole saw performed very well on the 1st cut but not so well on the 2nd and 3rd cuts. This only means that the diamond abrasives were lost at the end of the 1st cut.
It is important to note that these diamond hole saws need to be used with effective water cooling.
If you do not use water or if you apply too much pressure, the tip of the hole saw will overheat. The electroplated bond will locally lose strength causing the diamond abrasives to separate.
If you have efficient cooling, 200-300 RPM speed, and mild tool pressure, you can cut 10-20 holes in glass depending on the glass thickness.
Some of our customers are able to drill 30 bottles with one bit.
Diamond hole saw are used for brittle materials such as glass, ceramic, porcelain, granite, etc.
Pilot bits are usually not good for brittle material applications. They tend to make a crack before the hole saw starts working. The crack propagates and ruins the project.
Instead of a pilot bit, our DRILAX sets comes with a tough poly insert with can be used as a guide to hold the diamond hole saw steady.
You only need the insert for the few turns. You can continue free hand once the diamond hole saw makes the initial mark.