Drilling into sheet metal ?

D

dvddvd

Well-Known Member
Have some thin polished aluminium sheet when i tried to drill a hole of 13 mm with a twist drill it just caught as it went through and rived it all to bits, the metal must be only <1mm..any ideas how to drill a nice clean hole ?
 
Drill in spurts. Dabs. Pulses.

You know ?

Push, push, push, push.


Rather than Puuuuuuuusssshh.

Learn to pull away when it starts to bite.

Mr. HandyAndy - really
 
I think the problem is the drill bit, because its quite large 12 mm the twist bit on it is large, can you get big bits with a finer twist bit, so its not so savage when it grips (goes through) ?
 
Take the advice above. You'll be fine.



Mr. HandyAndy - really
 
The Q-Max cutter works by you drilling a hole large enough for the bolt (it doesn't matter if theis hole is a bit ragged, as it will be in the waste). Then you place one half of the cutter over the hole on one side of the sheet, the other half on the other side, thread the bolt through and tighten with hex key until it cuts through the sheet. This will give a very clean cur.

BB
 
Q-max is good but 13 mm is quite small, drilling thin sheet metal is not easy as explained above. sandwiching is a good idea but using metal underneath is better than wood as the drill can still be dragged through by the helix, wood may not resist this well enough. In theory you can regrind the point of the drill to a very flat angle but 1mm is probably too thin, what you are trying to achieve is for the outside diameter of the drill to be cutting into the sheet before the tip breaks through.
 
There are tapered reamers available that will open out, say, a 1/8" hole out to 13mm. Drilling that size hole should be easier.
http://www.chronos.ltd.uk/cgi-local/sh000001.pl?REFPAGE=http%3a%2f%2fwww%2echronos%2eltd%2euk%2facatalog%2fsearch%2ehtml&WD=tapered%20reamer&PN=Modelcraft_Reamers__Drills___PinVices%2ehtml%23aPDR0074#aPDR0074
Quick tip - when using a tapered reamer, slide an appropriate size washer over it first, so you know when to stop reaming.

Think I've seen hole saws available down to about 1/2" somewhere as well
 
Hi dvddvd.
I know i'm a little late on this thread but i will give you the answer just in case you need to do it again.

This takes me right back to my apprenticeship 30 years ago.

You need to grind your drill into a fishtail. This is done by using the edge of the grindstone rather than the diameter. The idea is that you still keep the leading edges of the 2 Rake angles higher than the back, but you end up with a point in the centre of the drill which is a couple of millimetres longer than the cutting edges. This allows a small hole to be pierced in the centre and the point acts as a Mandrel before the cutting of your desired hole actually starts, very similar to a Holesaw.

I wish i could do you a drawing on here.

Hope this helps.

Steve.
 
Where you been Hitch? no heard from you for a while.
PS I suggested the stepped drill a month ago

Methinks he has drilled a 13mm hole in his head, and is trying to work out when to pull the drill bit back out.
Either that or he had clamped the aluminium between two sheets of ply, and can't undo the clamps yet...
 
Your wrong im afraid, i clamped my head between two pieces of plywood, then drilled a 13 right through and out the other side. :-/
 
Surely you're not attempting to drill the 13mm hole in one go?

Pilot hole of say 3mm, then go up in bit size gradually. More time, but it won't ruin your ally sheet
 
You must log in or register to reply here.
Back
Top