Drilling Aluminium

[Bigwhiterabbitt]

Slowly starting to learn what I can and can't do (can do it its just a bit harder lol..). I know if I want to drill a larger hole in aluminium I need to drill a smaller hole 1st but how far do you take this? For example if I'm drilling say a 5mm hole do I need to go smaller 1st to stop the drill wandering etc..?

 

[bronbunbet]

A hole that size with ally will be fine if you go nice and slow also dependant on the thickness of the ally you are drilling though. Centre punch the initial place you are going to drill to give it that initial bite and some form of cutting grease on the drill bit too as ally will clog it quite quickly and slowly does it.

 

[Bigwhiterabbitt]

Thanks Bron.. I've been taking it slow on some practice pieces and its going quite well. Got a few triangular holes 1st couple of times with the larger drill bits but learning as I go. Never realy worked with aluminium before apart from where neatness didn't really matter. How would you reccomend setting about a 9mm hole. I tried a few starting off with the 5mm bit but lining the bigger one up after that was a bit tricky. I have to adjust the hight of the vice between bits and line it up again afterwards..

 

[bronbunbet]

It shouldn't be too hard if you go nice and slow as it'll find its natural centre of the 5mm pilot hole as such or you could go slightly smaller for a pilot if you are finding the bits you have don't have the required bite on initial startup say 3mm pilot. I worked with ally for years and it can be a bitch if you're not used to it, but a well greased or lubed drill bit and steady pace always pays dividends.

 

[Bigwhiterabbitt]

You mean 3mm then 5mm then 9mm or just 3mm and straight to 9mm ?

 

[bronbunbet]

3mm then 9mm but it all depends on the thickness too of your workpiece and quality of the the drill bit you're using matey. As I said above if it's a decent drill bit and you go nice and slow it'll pick it's true centre up after the first revolution of the drill bit ☺

 

[Bigwhiterabbitt]

Cheers.. Thanks for the help..

 

[Jasen]

Like bronbunbet said, step up bit size, slow speed and some type of oil preferably cutting oil. Aluminum tends to stick to cutters and can hang on to the bit/teeth and or clog them reducing cutting ability and cleanliness of cut.

 

[BaDaBooM]

Drilling aluminum is pretty hard task because its soft, the drill will grab the material instead of cutting & it will pull/stretch leaving an uneven hole. Its almost better to use a blunt drill. Using a new drill don't pre-drill with a smaller drill, just drill it with confidence (unless it really big hole +10mm).

 

[Bigwhiterabbitt]

Its just holes for buttons and the 510 so 5mm and 9mm. It's just a cheap drill press I got a long time ago and pulled out of the back of the shed lol.. it says the max speed is 2650 not ideal.. might be better just using my hand drill..