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Diamond Core Drills 3.5mm - 65mm

MDCD
  • Sizes from 3.5mm - 65mm
  • Cutting rim with slots for faster cutting
  • Clearance hole on the side

Diamond Core Drill Bits for Drilling Stone, Tile, Glass Bottles, Shells, Ceramic, Concrete, Porcelain and more...

These diamond core drill bits are still our most popular tools for drilling through hard materials. Sometimes referred to as diamond hole saws or diamond coring drills, they will produce a hole in whatever you put in front of them.

Read on for more detailed information such as which sizes you will be able to use in your Dremel rotary tool along with technical specifications, including the approximate inner core diameters of each.

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Description

Very common with hobbyists, scientists, craftspeople, glass artists, fossil preparators, builders, plumbers, shopfitters and DIY enthusiasts.

These diamond core drill bits are used for drilling holes in bone china, porcelain plates, glass, ceramic, fossil, bone, mirrors, stone, concrete, brick, bathroom tiles and fish aquariums.

Whether you are interested in purchasing just one diamond core drill bit for a DIY or craft project, or hundreds of diamond drills as a professional tradesman, we have the right sizes for you. 

Diamond drills for drilling tiles are essential and will drill holes far easier and with a smoother cut than any other tile drill bits.

Jewellers looking for diamond core drill sizes as small as 1mm - 3mm, please take a look at our Small Diamond Core Drills range. Alternatively, our most popular Small Diamond Drill Bits range has sizes from 0.75mm - 3mm here.

If you are using a hobby type rotary tool such as a Dremel you can use the 3.5mm size in this range, or you might like to try our 3mm Small diamond core drills with a 2.7mm shank, or our 6mm Bottle Neck Diamond Core drills, which have a 2.35mm shank.

Helpful Note: The size indicated refers to the size of the hole you will end up with. 

If you are looking to achieve a core rather than drill a hole please see the technical tab for the internal diameter of each core drill. For example, if you need to extract a 3mm core, choose the 5mm diamond core drill bit. 

Alternatively, use our Thin Wall Diamond Core Drills, which are specifically designed for extracting a core.

Tip: Use with plenty of cold water, slow speed and low pressure

Helpful note: If you find the drill bit skittering across the surface of your work angle the drill to make the initial cut and then continue to drill vertically. Alternatively, you can adhere a piece of masking tape where you require the hole to be, or make a very simple 'V' template out of a piece of wood similar to the one shown in our blog article 'How To Make a Stone Tea Light Candle Holder'

"Results were impressive for boring through porcelain tiles. All holes being perfect, no chipping. The bits sailed through the tiles no problem only took a couple of minutes and the job was done" - John (Monafissel)"
"Your 6mm diamond core drill bits have been excellent. I had 200 plates to drill with 6 core drill bits and they have performed so well that I was able to spare one for a friend!" - Maggie MacMillan-Scott"
"The core drill bit is absolutely fantastic, for years I have avoided drilling glass and ceramics, now there's no stopping me" - H.Maclennan"

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.


Technical

Diamond Hole Cutter, 120# Diamond grit which is precisely electroplated onto a steel shank
Drilling Depth: from 25mm to 35mm

Sizes stated are +/- 0.2mm

Wall thickness: 1mm - 1.5mm

Please note. These diamond core drills have been manufactured with a precision outer diameter for drilling a hole, To drill a core, the inner core diameter sizes are shown below but should be taken as an approximate measurement. For precise inner core extraction, please use our Thin Wall Diamond Core Drills

3.5mm Diameter

  • Overall length: 42mm
  • Shank: 3.0mm
  • Approx. Inner core diameter: 1.5mm

4.0mm Diameter

  • Overall length: 50mm
  • Shank: 3.5mm
  • Approx. Inner core diameter: 2.5mm

5.0mm Diameter

  • Overall length: 50mm
  • Shank: 4.4mm
  • Approx. Inner core diameter: 3.5mm

6.0mm Diameter

  • Overall length: 50mm
  • Shank: 5.3mm
  • Approx. Inner core diameter: 4.0mm

7.0mm Diameter

  • Overall length: 50mm
  • Shank: 6.0mm
  • Approx. Inner core diameter: 5.0mm

8.0mm Diameter

  • Overall length: 50mm
  • Shank: 6.5mm
  • Approx. Inner core diameter: 6.0mm

10mm Diameter

  • Overall length: 50mm
  • Shank: 6.0mm
  • Approx. Inner core diameter: 7.8mm
  • Internal core depth: 25mm

12mm Diameter

  • Overall length: 50mm
  • Shank: 6.0mm
  • Approx. Inner core diameter: 9.5mm
  • Internal core depth: 25mm

14mm Diameter

  • Overall length: 50mm
  • Shank: 6.5mm
  • Approx. Inner core diameter: 11.5mm
  • Internal core depth: 28mm

16mm Diameter

  • Overall length: 50mm
  • Shank: 8.0mm
  • Approx. Inner core diameter: 13.5mm
  • Internal core depth: 28mm

18mm Diameter

  • Overall length: 50mm
  • Shank: 8.0mm
  • Approx. Inner core diameter: 15mm
  • Internal core depth: 26mm

20mm Diameter

  • Overall length: 50mm
  • Shank: 8.0mm
  • Approx. Inner core diameter: 17mm
  • Internal core depth: 26mm

22mm Diameter

  • Overall length: 50mm
  • Shank: 8.0mm
  • Approx. Inner core diameter: 19.5mm
  • Internal core depth: 26mm

24mm Diameter

  • Overall length: 50mm
  • Shank: 8.0mm
  • Approx. Inner core diameter: 21mm
  • Internal core depth: 26mm

25mm Diameter

  • Overall length: 50mm
  • Shank: 8.0mm
  • Approx. Inner core diameter: 22.5mm
  • Internal core depth: 26mm

26mm Diameter

  • Overall length: 50mm
  • Shank: 8.0mm
  • Approx. Inner core diameter: 23.5mm
  • Internal core depth: 26mm

28mm Diameter

  • Overall length: 55mm
  • Shank: 8.0mm
  • Approx. Inner core diameter: 25.5mm
  • Internal core depth: 26mm

30mm Diameter

  • Overall length: 55mm
  • Shank: 10mm
  • Approx. Inner core diameter: 27.5mm
  • Internal core depth: 26mm

31mm Diameter

  • Overall length: 55mm
  • Shank: 10mm
  • Approx. Inner core diameter: 28mm
  • Internal core depth: 26mm

32mm Diameter

  • Overall length: 55mm
  • Shank: 10mm
  • Approx. Inner core diameter: 29.5mm
  • Internal core depth: 26mm

33mm Diameter

  • Overall length: 55mm
  • Shank: 10mm
  • Approx. Inner core diameter: 30mm
  • Internal core depth: 26mm

35mm Diameter

  • Overall length: 55mm
  • Shank: 10mm
  • Approx. Inner core diameter: 32mm
  • Internal core depth: 26mm

38mm Diameter

  • Overall length: 55mm
  • Shank: 10mm
  • Approx. Inner core diameter: 35mm
  • Internal core depth: 26mm

40mm Diameter

  • Overall length: 55mm
  • Shank: 10mm
  • Approx. Inner core diameter: 37mm
  • Internal core depth: 26mm

42mm Diameter

  • Overall length: 55mm
  • Shank: 10mm
  • Approx. Inner core diameter: 39mm
  • Internal core depth: 26mm

45mm Diameter

  • Overall length: 55mm
  • Shank: 10mm
  • Approx. Inner core diameter: 42mm
  • Internal core depth: 26mm

48mm Diameter

  • Overall length: 55mm
  • Shank: 10mm
  • Approx. Inner core diameter: 45mm
  • Internal core depth: 26mm

50mm Diameter

  • Overall length: 55mm
  • Shank: 10mm
  • Approx. Inner core diameter: 46mm
  • Internal core depth: 26mm

55mm Diameter

  • Overall length: 55mm
  • Shank: 10mm
  • Approx. Inner core diameter: 52mm
  • Internal core depth: 26mm

60mm Diameter

  • Overall length: 55mm
  • Shank: 10mm
  • Approx. Inner core diameter: 56mm
  • Internal core depth: 26mm

64mm Diameter

  • Overall length: 60mm
  • Shank: 10mm
  • Approx. Inner core diameter: 61mm
  • Internal core depth: 26mm

65mm Diameter

  • Overall length: 60mm
  • Shank: 10mm
  • Approx. Inner core diameter: 62mm
  • Internal core depth: 26mm

Questions & Answers

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Other questions and our answers

Are the diamond core drills suitable for a generic drill or does it need any coupling device? Thanks in advance.

Ricardo Belda González

Yes, the diamond core drills are suitable to use in a regular, generic drill, no adaptor is needed. Thanks for your question Ricardo, I am sure others will find this helpful too. 

I want to get a cylinder core out of stone. Is this possible?

Marianne

Thanks Marianne, a good question. Yes, this certainly is possible and we have lots of customers who use them for just this purpose. However, please note that the diamond core drills are intended for drilling a hole rather than extracting a core so we cannot guarantee the precision of the cylinder.  Take a look at the technical tab to find out the internal diameter of the diamond core drills so you know which size to order. 

Do you have something that will bevel around the area of glass where I’ve just drilled my hole please? Thanks

Sara Pringle

We have a wide range of diamond files perfect for this (try the 600 grit medium diamond files) or you could try  smoothing it with a diamond hand pad. If you want to go further and create a smooth, shiny finish, then we have various polishers and abrasives that will do this.

Hi, whilst looking for some small diamond bits I happened to read your bit about using core drills to make tea light candle holders, do you do a set of the sizes required to do this?

Take a look at this article: How to Make A Beautiful Stone Tea light Candle Holder in 4 Easy Steps

There's a full tutorial of how to make a tea light candle holder with links to the product pages of the bits you'll need (42mm diamond core drill to make the initial hole and a smaller one to break down the core you're left with) and a diamond cylinder burr for smoothing out the blind hole. 

Hello, If I purchase diamond core drills, how can I keep them from skating around on Bottles, especially say 16mm size or so, without a starter bit ?. Also is it possible to drill this size hole in Bottles with the v tip ,type of glass/ tile drill, which would tend to get a bite amost immediately ?. Any help appreciated. Regards Ken.

ken garside

We've tried all manner of drill bits over the years and we find the core drills most efficient at cutting, especially if you want a nice clean hole (you can't get this with the V-tip bits). Depending on what type of drill you're using we have either the standard core drills for use in a regular drill, or the Bottle Neck Core drills - ideal to use if you're using a Dremel type drill with a chuck.  

To prevent the drill bit from skittering across the surface, angle the drill before the initai cut. Once that first chip-cut is made put the drill to a vertical position and continue drilling through.  If it's convenient to do so you can also add a strip of masking tape. Personally though I find this clogs the diamond grit up a bit and it can be a bit more fiddly.
These are a couple of articles we wrote that may help. The first is how to cut a hole in glass bottles and the second is cutting a glass bottle. 

https://www.eternaltools.com/blog/how-to-drill-a-hole-in-glass-bottles-infographic

https://www.eternaltools.com/blog/bottle-cutting-how-to-cut-a-glass-bottle

Will the 3mm shank fit a Dremel tool?

Pat James

You will need the Dremel Multi Chuck attachment or Dremel Collet Nut Kit in order to use these drills with your Dremel rotary tool.  We recommned the multi chuck over the collet nut kit as you don't need to keep changing the collets.

If you would like to try a variety of sizes of drill bits, we do the Diamond Drill Bits set for your Dremel Tool. This includes the chuck along with an assortment of diamond drill bits.  

There's more detailed information on the product page under the 'Description' tab and 'Technical' tabs.




Are these suitable for drilling into hardened steel ? I want to drill out a hardened steel tap that I have broken in a hole in an aluminium casing. The broken stub is too hard to drill out with a conventional HSS drill.

Julian leyton

HI Julian, 

The diamond coated core drills are only to be used on glass , stone and ceramic type materials. They are not for drilling holes in metal. 

If the HSS is not strong enough you will need to use a tungsten carbide drill bit such as our carbide micro drill bits

Alternatively you can grind out the stub using a tungsten carbide burr. We have lots of diameter sizes, shank sizes and shapes of the tungsten carbide burrs.




we wanted to make a 5mm hole. Is that possible? In stones from the beach.

kent francis

Yes, you will need a 5mm diamond core drill.

This blog article will help show you how to drill the holes through the pebbles you have:

https://www.eternaltools.com/blog/how-to-drill-pebbles


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