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Extra Long Shank 3mm Diamond Drill Bits


***New Improved Design*** These 3.00mm x 100mm extra long shank, small diamond drill bits are ideal for drilling 3mm holes in hard materials such as glass, stone, ceramic, porcelain, shell, bone and fossils when the depth of the material requires an extra long shank to the drill bit. These long drill bits prevent your drill from hitting the material whilst drilling. 

Very popular with lapidarist, glass and stone artists, jewellers, restoration and conservation workers and Scientists. These long drill bits are solid throughout, not hollow.

  • Overall length: 100mm
  • Diamond Working length: 20mm
  • Diameter: 3mm
"I especially find the extra long diamond drill bits helpful because I’m drilling through beach stones about 2 inches thick. I’m using a battery powered Dremel and placing the stones in water. When in water, the bits wear very well" - Andrew Honig
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Tip: use these long drill bits with plenty of cold water, slow speed, low pressure

For further information, you may like to read our article: '12 Things You Should Know About Diamond Drill Bits'

Disclaimer. Using rotary tools near water has never been, to the best of our knowledge, endorsed by any of the rotary tool manufacturers. If you do choose to drill near water or with attachments under water connected to your drill then you do so at your own risk. Please be aware that mixing electricity and water can be very dangerous.


Diamond grit is precisely electroplated onto a solid steel shank

Diameter: 3mm

  • Overall length: 100mm
  • Diamond grit: 180#
  • Diamond tip length 20mm
  • Shank diameter: 3mm

Questions & Answers

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Other questions and our answers

Will your drill bits fit my drill?


Our drill bits will fit all rotary drills so long as you have an adjustable collet or chuck with which to hold the shank of our very small drill bits. Sometimes when buying a drill they will come with an adjustable collet but if you find you are in need of one then we supply either a Dremel Multi Chuck (DMC4486) or a Dremel Collet Nut Kit (DCNK4485).

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