I have no prior knowledge of drilling but I've stripped a screw on one of my electronics so I need to drill it out to access the insides for a fix.

From basic research, I understand that the 'drill chuck' is the hole on the drill where the bit sits. However the majority of drills are suited for 'normal' sized bits.

So before I make the wrong purchase, I'd like to know what drill + bit combination I need for holes between 0.5-1mm?

  • 2
    You're very likely to break those tiny bits in a regular-sized drill, even with an appropriate adapter. I think you'd be better off buying a small "Dremel" knock-off which is made for tiny bits.
    – brhans
    Commented Oct 11, 2018 at 11:55
  • Have you tried using an elastic band between the stripped screw head and the screwdriver and undoing it? Is it a recessed screw? Commented Oct 11, 2018 at 13:57
  • In light of the edited typo, I think we have an XY problem here. Instead of drilling the screw out, I'd be looking for an alternative way to grip it. Cutting a slot often works.
    – isherwood
    Commented Oct 11, 2018 at 14:02

3 Answers 3


One option that you have is to use a mini-drill chuck adapter or mini-drill chuck. I used the latter term in a search and the auto-fill in The Google added adapter, but the results were the same:

mini drill chuck

This image came from The Home Depot and will accept from 0.00 inches to 0.039 inches (1 mm) according to the specifications. You would find other mini-drill chucks with larger capacity.

I dislike the four-jaw configuration, but it's less expensive than a three-jaw chuck. It's easy to get a tiny drill bit misaligned when securing it in a four-jaw design.

My initial search appeared at first to return only four-jaw designs, but I was able to locate a three-jaw eventually:

3 jaw mini drill chuck

It has a price similar to the Home Depot version, but appears to be an online resource known as iOffer.


If you're drilling a hole that small near sensitive electronics, you may want to consider a pin vise. They are often available at hobby stores.

Here's a picture of one of the first ones I found via Google: enter image description here
Image courtesy of wonkeedonkeetools.co.uk (with a nice description of use), no product reference implied.

The top (of some) pivot so you can place a finger there to hold it, then you rotate it by hand. You can even rotate back-and-forth instead of constantly in one direction (because it's easier) and you'll still make a hole. They're very effective at drilling through plastic and pretty reasonable for thin metal.

Doing it by hand, you'll be much less likely to do damage to the surrounding areas by having the bit accidentally drift off course or by overdoing the hole and going through something on the other side that you didn't intend to drill through.


I think you misunderstand the nature of a good drill's chuck. As you can see from other photos on this page, a chuck is essentially at zero size when fully closed. It's able to accommodate virtually any size bit up to its bore diameter, which is typically 1/2", but may be only 3/8" with older or small drills.

I routinely use bits down to 1/16" in my DeWalt drills, and I'm reasonably sure that they'd do half that without issue, should I find the need.

As an alternative, simply purchase hex-shank bits which will be securely held by even a worn traditional chuck.

  • I find that the standard chuck doesn't work for small bits because the bits are too short, so that an adapter or a smaller drill works better. Commented Oct 11, 2018 at 13:35
  • Trouble with tiny (1/32") or so bits in a drill is that they are so easy to break when you fail to hold drill at precisely the same angle throughout the boring. The small ones have some flexibility, but that repeated strain causes the bit to break. I'd go with a drill press or mounted rotary tool with the mini chuck adaptor fred_dot_u mentions. You'll still break bits, so have spares. Commented Oct 11, 2018 at 19:32
  • 1
    I have had drill motors in the past with chucks that do not close to zero. Drill bits below 1/16" or 1.5 mm will not hold in that type of chuck. In the search performed for the answer above, I noted that some of them also reference non-zero minimums.
    – fred_dot_u
    Commented Oct 11, 2018 at 21:06
  • I have too but the question presupposes this situation needlessly.
    – isherwood
    Commented Oct 12, 2018 at 0:14
  • Trouble is, using a big(gish) drill with a tiny drill bit gives potental problem - the whole thing is unweildy, the machine is heavy for a thin bit, it may obscure the work. Into wood, metal, etc., not so much a problem, but onto a pcb? I wouldn't.
    – Tim
    Commented Mar 7, 2021 at 10:52

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