For Drilling Glass, Stone, Marble and Porcelain
Our Diamond Plated Core Drill Bits will give you great service when used carefully with CRL Diamond Coolant and a true running machine. Diamond drill life, cutting rate and finish do vary, depending on the equipment condition, speed (RPM), concentricity of the chuck, user feed rate, and type of glass being used.
Diamond Plated Core Drill Bits will fit into any regular manual drill or a drill press running at 500 to 2000 RPM. The higher the RPM, the more efficient the drill bit will be, and bit life may increase. Recommended Operating Speeds (to be used as a guideline):
1/8" to 1/2" Diameter 1,600 - 2,000 RPM
5/8" to 1" Diameter 1,400 - 1,600 RPM
1-1/8" to 2" Diameter 1,100 - 1,400 RPM
2-1/8" to 3" Diameter 900 - 1,100 RPM
3-1/4" to 4" Diameter 700 - 900 RPM
4-1/2" Diameter and Larger 500 - 700 RPM
Place a Suction Base Retaining Drilling Ring around area to be drilled and pour in CRL Diamond Tool Coolant mixture. NEVER run a diamond drill dry. Please, remember that Suction Base Retaining Drilling Ring will stick only to a flat surface of glass, stone or tile. If you intend to drill holes in glass blocks, please, check if the drilling surface is flat. If it is not even or you are going to drill on the side of the block a Suction Base Retaining Drilling Ring will not be useful. There is a trick that you can use in this case: make a doughnut out of children play dough, put it on the surface conforming it to the curvature of the surface. It will become more or less usable replacement for a Suction Base Retaining Drilling Ring. It will not retain the CRL Diamond Tool Coolant mixture as well as a Suction Base Retaining Drilling Ring would but it will free you from the task of constant pouring the CRL Diamond Tool Coolant mixture in the drilling area.
Be sure the drill is running concentric and the machine's chuck has no wobble.
Using medium pressure, feed the drill into the glass for five seconds, then back up the bit to allow coolant to flow into the cut. Lower the drill with medium pressure again for five seconds. Keep repeating until you are within 3/32" of being through the glass, then lighten up on the pressure and ease the bit through the last 3/32" of the glass to reduce breakout. Note: a hard surface under the glass (hard board or wood) reduces breakout.
Always be sure, after each hole is drilled, that the glass plug is removed from the drill. Holes are provided in the side or on the top of the cylinder for easy removal. Multiple plugs will sometimes jam inside the drill, and while you are removing them, the drill might be damaged or bent out of round.
It is important to know that, when using a diamond drill, there will always be a certain amount of breakout or flare on the back side of the hole. This is because when the glass becomes so thin that it can no longer support the weight or pressure of the drill, the slug and remaining thin piece of glass will chip out.
Use CRL Sharpening Stone to expose a fresh layer of diamond crystals. The CRL Sharpening Stone can only be used once, lightly on plated style drill bits during their life time. But it will increase life of a drill bit almost twice! For your safety always use stone larger than the drill that you are sharpening. A small stone can catch and spin in the drill causing injury to the operator. To sharpen: submerge stone in the tray of water before use to fully saturate stone. Position stone securely under your drill bit mounted in the machine. Block or hold stone securely to prevent spinning. Drill into wet stone to 1/4" depth, lift, move stone over slightly, and drill again to 1/4" depth. Doing this only several times should be enough for the drill to perform better with fresh diamonds in contact area. Now try drilling your glass again. Your drilling performance should be greatly improved. Use CRL Sharpening Stone when your diamond plated drill becomes slow in drilling. Don't overuse stone. Only light dressing is needed to expose fresh diamonds.