1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

What drill bit do I need for making big holes?

Discussion in 'Wood / Woodwork / Carpentry' started by OM2, 31 Mar 2018.

  1. OM2

    OM2

    Joined:
    18 Jan 2007
    Messages:
    580
    Thanks Received:
    1
    Country:
    United Kingdom
    I want to make upto 10cm in diameter in holes. Only need for wood.

    What drill bit should I be searching for?

    The ones I find are labelled for electricians + quite expensive.

    I would love a clean cut hole...
    But also is there some sort of rubber ring that I can put over to cover?

    Most the holes will be for tables and making holes so I can feed wire through

    Thanks
     
  2. Keithmac

    Keithmac

    Joined:
    10 Oct 2017
    Messages:
    1,185
    Thanks Received:
    190
    Country:
    United Kingdom
    Google Holesaw..
     
  3. Notch7

    Notch7

    Joined:
    15 Sep 2017
    Messages:
    13,592
    Thanks Received:
    1,061
    Location:
    Sussex
    Country:
    United Kingdom
    big wire then!
     
  4. TicTac

    TicTac

    Joined:
    21 Feb 2018
    Messages:
    391
    Thanks Received:
    68
    Country:
    United Kingdom
    You can get holesaws that are designed ti make access holes in floors etc, and you can then buy the covers to drop in place, but I'm not sure if this is exactly what you're after.
     
    Last edited: 31 Mar 2018
  5. Tigercubrider

    Tigercubrider

    Joined:
    22 Jul 2016
    Messages:
    2,576
    Thanks Received:
    369
    Country:
    United Kingdom
  6. KenGMac

    KenGMac

    Joined:
    24 Aug 2010
    Messages:
    2,433
    Thanks Received:
    421
    Location:
    Ayrshire
    Country:
    United Kingdom
    You could consider drilling smaller holes, each hole for say live feeds,, the other for Comms cabling and TV Cabling Etc makes for locating a suitable drill and insert cover easier?

    Just a consideration, after all a 100 mm Dia. hole is a beast with a load of break out problems with the edges?
     
  7. magicmushroom666

    magicmushroom666

    Joined:
    11 Jan 2010
    Messages:
    226
    Thanks Received:
    37
    Location:
    Essex
    Country:
    United Kingdom
  8. Tigercubrider

    Tigercubrider

    Joined:
    22 Jul 2016
    Messages:
    2,576
    Thanks Received:
    369
    Country:
    United Kingdom
  9. JobAndKnock

    JobAndKnock

    Joined:
    30 Sep 2011
    Messages:
    3,484
    Thanks Received:
    677
    Location:
    Lancashire
    Country:
    United Kingdom
    You need to drill from one side first until the pilot bit breaks through, then finish drilling from the other side. Much better finish

    The torque reaction on a 100mm holesaw calls for lower speed and extra care, as well as possibly a long side handle on the drill to avoid injury in the event of a "stick" (I use a Makita DHP480 cordless combi with a long side handle). Not advisable to use low power cordless drills unless you really want to burn the batteries out (by cooking them), I'd say. A drill press is really a better option if at all possible
     
  10. OM2

    OM2

    Joined:
    18 Jan 2007
    Messages:
    580
    Thanks Received:
    1
    Country:
    United Kingdom
    thanks for the replies guys.
    10cm? ok... maybe too big.

    @JobAndKnock now you've got me worried!
    i've got mango wood tables - they weigh an absolute ton.
    i didn't think it would be a problem?
    i dont want to go and buy a makita just for this!
    i've got a bosch cordless drill - but if u say it's a challeging job... i don't want to put it to the test!

    drill press - i could buy a drill clamp and use that?


    @Tigercubrider letterbox looks great. i'll consider. but for the first desk... i need a hole.

    EDIT just searched for 'desk hole for sockets'
    bingo
    i think the standard size is 80mm.
    they're called Desk Table Grommet.
    £1.50 delivered - crazy - the item MUST be more than 2.5cm = packet in Royal Mail.
     
  11. Nozzle

    Nozzle

    Joined:
    23 Dec 2012
    Messages:
    1,883
    Thanks Received:
    230
    Location:
    Suffolk
    Country:
    United Kingdom
    If you want to produce quality holes in nice wood - don't use a [hole] saw... Use a Forstner bit (using backing timber to avoid break-out) or a router (with a collar & template)

    Nozzle
     
    • Thanks Thanks x 1
    • Like Like x 1
  12. OM2

    OM2

    Joined:
    18 Jan 2007
    Messages:
    580
    Thanks Received:
    1
    Country:
    United Kingdom
    @Nozzle thanks for the advice. Sounds good.
    Backing timber... say if I'm drilling through... you are saying put a block of wood underneath?

    Router? Can you show me what you mean with a pic or video?
    Thanks
     
  13. JobAndKnock

    JobAndKnock

    Joined:
    30 Sep 2011
    Messages:
    3,484
    Thanks Received:
    677
    Location:
    Lancashire
    Country:
    United Kingdom
    You finally said 80mm which is a lot easier to deal with - at 100mm and above it starts getting a much more difficult! On shop fits I drill out 50 to 75mm holes in counters quite a lot with just an 18 volt cordless and a side handle (yes, I use the big drill, but in the past I used smaller ones) - ideally you want to drill half way through from one side, and the rest from the other, pulling the saw back regularly to clean-out the gullets between the teeth (which are pretty small). The carbide tipped hole saws with 2- to 4-teeth are actually better in that respect and clog less easily. One thing to note about hole saws is that the hole it cuts will not be clean-sided, so your inserts will need to have a flange or lip which covers the poor surfaces of the insides of the hole. TBH it doesn't matter that much so long as the inserts have flanges (most cable tidy inserts do)
     
    • Thanks Thanks x 1
  14. rsgaz

    rsgaz

    Joined:
    28 Jul 2014
    Messages:
    1,587
    Thanks Received:
    437
    Country:
    United Kingdom
    Here's a tip for that, you can massively speed up the time taken to drill a worktop with a holesaw.

    Just start the hole, maybe go 2mm deep.
    Using an auger (say, 12mm), drill all the way through, so that this 12mm hole slightly overlaps the groove made by the holesaw, like this...

    holesawtip.jpg

    It gives the dust somewhere to go and then you can go all the way through in one go with the holesaw. Chipboard is very frustrating otherwise, it's not just the binding/clogging and having to keep stopping, but the resin in the chipboard begins to overheat and boil/burn!

    Gaz :)

    edit
    : but as said, once the arbor pokes out the bottom, drill upwards with the holesaw a little bit for a cleaner hole.
     
    Last edited: 1 Apr 2018
    • Thanks Thanks x 1
    • Like Like x 1
  15. OM2

    OM2

    Joined:
    18 Jan 2007
    Messages:
    580
    Thanks Received:
    1
    Country:
    United Kingdom
    thanks guys.
    @rsgaz - oooh that's an awesome tip :)

    i'm a bit confused. what's better holesaw or Forstner drill bit?
     
Loading...

Share This Page