The best way is to put the drill in reverse

[Bill Wright]

I needed to drill some holes through softwood. They had to be 4mm diameter and the wood was 125mm thick. The 4mm drill bit wasn't long enough, so I used it as far as it could go, then got a bit of 4mm threaded bar and cut the end at an angle and sharpened the already sharp edge of the end. I then used this bar as a drill bit. It worked remarkably well, but when it had drilled through the wood the threads were gripped and it wanted to keep going down and down. I got it out by reversing the drill.

I made all the subsequent holes with the drill in reverse, so the thread was turning backwards. This solved the problem.

Anyone else got any remarkable tales of drilling long thin holes?

Bill

[Lobster]

On 28 Apr 2014, Bill Wright grunted:

Well if you think about it, it's completely arbitrary that the drills drill in a clockwise direction; it's a feature of the angles/direction of the cutting edge of the bit. If you fabricate your own drill bit then those parameters are entirely up to you.

Um... no more remarkable than nipping down to Toolstation and picking up a long, thin drill bit...

[Mike Barnes]

I don't think it's *completely* arbitrary if you look at early drills and take right-handedness into account.

[Tim Lamb]

In message , Lobster writes

Spoon bit in a hand brace? Surprising they haven't transferred to current use as you get a very clean hole.

>

[JimK]

Can you get extra long 4mm drill bits? I suspect they'd be liable to snap ?

Jim K

[Brian Gaff]

So you could not run to a proper wood drilling bit then?

You know the ones witha point and a flat bit with blades on? Brian

[Tricky Dicky]

It was a old woodworkers trick to use a panel pin with its head snipped of to produce a similar edge, as a pilot drill for inserting panel pins in har dwood. A similar homemade drill is the D-bit, using a steel bar of the same diameter as the required hole. This was then filed half way through to pro duce a flat on the side, the remaining D shape on the end was filed back at an angle to produce a cutting edge. Although principally designed to produ ce flat-bottomed bores to already drilled holes it can with a lot of care a nd re-sharpening used to drill deep bores, needs frequent withdrawing to cl ear swarf.

Richard

[Dave Liquorice]

Required driling depth 125 mm so the drill overall has to be greater than that at least 150 mm. That is going to be fragile but start with a normal 4 mm and then swap to the long one and be careful ought to be OK.

Does "long thin holes" extend to 24" and 20 mm? Drilled through rubble stone wall with the SDS and 1000 mm long bit, seemed to take a while and didn't produce much dust. Wasn't until I'd finished that I noticed the drill was in reverse...

[Yendor]

What a Speedbit. Don;t think I have ever seen a 4mm speedbit