Drilling Aluminium Sheet with Woodworking Tools

[aesmith]

Hi,

Sorry for a metalworking question. Depending on how things turn out, I may want to create an aluminium plate with a series of accurate 14mm holes, 21 holes in total. The metal will be probably 1mm thick.

I don't have special metal working tools, let alone machines, but I wondered whether woodworking drill bits would be up to the job of drilling aluminium. The biggest conventional twist bit that I have is 10mm, and I really don't fancy filing each out to size. Would forstner bits do it? Or any other brainwave?

I have a pillar drill, and making a mock-up in softwood I was quite happy with the accuracy using a forstner bit drilling to pencil marks for the hole centres.

Thanks in advance,

 

[Racers]

Hi,

You will have to get a step drill http://www.axminster.co.uk/product-Axmi ... 576690.htm these are made for sheet metal and will cut your holes with no problems, I use them with a little oil and they do rub a bit and can get hot causing a big burr on the back side, which is easily cleaned off by drilling from the other side.

Pete

 

[SeanG]

I've never used one but in a sheet metal work book I read the recommendation was to use a hole punch

http://www.thesitebox.com/Category/4843/sheet-metal-hole-punch.aspx

you drill a smaller hole for the threaded part, assemble the punch through the pilot hole, tighten the whole thing up and it sheares the bigger hole - suposed to be very precise. :?: :?:

 

[aesmith]

Thanks for both comments. Hole punch would definitely make the hole, I've used them before. They might cause a bit of distortion. I've not used those tapers cutters, but again no reason to think they won't work either.

I was hoping to do the job without buying a special tool, but I've just remembered that I haven't asked around at work so I'll do that now I have some more ideas about what to look for.

 

[Racers]

Hi,

A sheet metal punch will build your arms up! step drill will be much faster and have less of a chance distorting the metal.


Pete

 

[RobertMP]

1mm thick ally you might get away with a forstner bit. ally is sticky stuff to cut so keep it lubricated. We used to use paraffin for punching it though even then it would sometimes grip the punch. WD40 works too.

Whatever you do with the drill just stay aware of the dangers of the drill bit sticking to the ally sheet and spinning it round.

Time consuming and you will still have to drill pilot holes but a Q-max cutter will do the job

Just google Q-Max . picture came from here

 

[MikeG.]

OK, this isn't a wind up.......but you can use spade bits! Make sure that the work is held down well, and drill a pilot hole 3-5mm diameter.....then, ignoring all the noises, use a sharp spade bit. Beware that the metal it throws off is reasonably warm.

Mike

 

[aesmith]

Whatever you do with the drill just stay aware of the dangers of the drill bit sticking to the ally sheet and spinning it round.

Agreed. Wouldn't want to spoil the job.

Seriously I was thinking best method would to make the plate oversize and screw it down onto a piece of sacrificial board, MDF or whatever's to hand. I would use a fence on the drill table in any case to maintain the hole spacing. It should be possible to make sure it can't rotate.