Small Diamond coated ‘tipped’ Drill bits 0.75mm – 3mm

The facts and fiction about Diamond Drill Bits

1. What Material to use them on.Diamond drill bits are perfect for drilling through glass, sea glass, stone, gemstones, ceramic, porcelain and shell. DO NOT use Diamond drill bits on metal or soft wood. Metal and some wood is too soft a material and will cause the diamonds to clog up on your drill bit. Carbide drill bits are an excellent choice for metal and wood.
For fused glass and very hard sea glass, you will want to use the diamond core drills.
Diamond is the hardest material and therefore, anything else can be cut or drilled with it. If you are cutting or drilling through very hard materials such as sapphire then bear in mind you will need alot of patience and perhaps more drill bits than you would if you were lets say drilling through glass or Opal.

2. Diamond Core Drills. Diamond core drills  allow the water to flow up inside the drill as you’re drilling helping to prolong the life of your drill bit plus helping to prevent any cracking or shattering of the material you’re drilling. If you find debris gets stuck inside your core drill, drill up and down into the water a few times to remove this excess. Water is ideal to use as your lubricant when drilling. There are oil based lubricants out there but it’s not necessary to go to the expense of buying these.

Diamond Sintered Burs, various shapes

3. Coated Versus Sintered. Electroplated, coated or bonded means the diamonds are coated onto the steel shaft/shank in a single layer, therefore once this layer has worn away, the drill bit will need to be replaced. Sintered diamond drill bits or burs have several layers of diamonds and therefore last a very long time but will also be more expensive than coated diamond drill bits. The sintered diamond bits can be cleaned/dressed using an aluminium oxide stone before use and during, thus revealing a fresh layer of diamonds each time.

4. The life of your drill bit is dependent on many factors. Your diamond drill bits lifetime will depend on certain factors: speed, lubricant, pressure and the density of the material you’re using. Take a look at our Mohs Scale of hardness to see the comparisons between different materials. Be aware that drilling through hard gemstones can take a long time, be patient, you’ll get there in the end.

5. Attaching Diamond Drill bits to your Drill. Very small diamond drill bits ranging in sizes between 0.75mm – 3mm won’t fit into a rotary hand piece drill or DIY drill without the appropriate collet or chuck to hold them. Dremel do a couple of attachments which will fix to your drill: The Dremel Collet Nut Kit and the Dremel Multi Chuck. Roughly about half of the diamond drill bit shank should be in your drill, leaving half of the drill bit exposed.

6. Overheating/Speed/Pressure/Diamonds coming away. If you smell burning, back off! You’re speed is too high or the pressure you’re applying is too much. You’re drill bit should never be hot to the touch, not even warm. Start your speed off slow and increase as the drill bit goes through your material too higher speed will cause the drill bit to overheat and your material to crack. If the diamonds chip away from the shaft it is probably due to too much pressure – let the drill do the work and apply very little pressure. Feel your way through your material. If in doubt, practice on a garden pebble until you get used to the technique. The general rule is the smaller the diameter of your drill bit, the faster you can go. However, the harder your material the slower you should go.

Take a look at teacher and jewellery artist, Melissa Muir’s video at the bottom of this page as she shows how to correctly use speed with your drills.

7. Is it Safe to use Water near the Drill? When drilling any kind of material you should wear goggles and gloves to prevent any flying bits of debris from causing injury and the same care should be applied if you’re using water near your drill. It’s safe to do so but with care. Water can either be fed onto your material via pump, a running tap, a drip feed or to immerse your material in the water ensuring about 1cm of water covers your material.

8. How to Start Drilling your Hole. Angle your drill to start off the drilling to prevent the drill bit from skittering over the surface of your material, once the initial hole is made you can drill from a vertical position. To see more tips on how to drill various materials take a look at our Tutorials section. How to Drill Sea Glass? is a popular one.

9. Opening up Holes. Diamond twist drills are intended to open up holes. Very popular with bead artists to increase the size of holes in glass beads. Also handy to prevent condensation build up in the windows of your house.

10. Tempered Glass. Do not attempt to drill tempered glass with diamond drills, you will end up with cracked glass

Large Diamond Coated Core Drills from 4mm – 50mm

11. Obtaining a Core. Diamond core drills are intended to make a hole, not to obtain a core. However, many of our customers use them for just this purpose to extract a core of fossil lets say for DNA testing and do so with great success, although we can’t guarantee the precision of the core.

12. Speed to use drill bits at. Use your diamond drill bits at slow speeds, especially when making the initial hole. This will prevent any breakages of your material and help maintain the life of your drill bit.