Drilling Aluminum


I'm installing a support bracket for a small window ac, but I'm stuck on drilling through the window sill. I know aluminum is a difficult material but I tried both titanium and cobalt bits. I made a small hole but it's refusing to go any deeper. Any advice?

Apr 24, 20 2:57 pm

Are you sure it's aluminum?  Actually, even high-quality aluminum alloy isn't difficult to drill.  Be sure your drill isn't set on reverse rotation.

Apr 24, 20 3:18 pm  · 
1  · 

+1, does not sound like alu

Apr 24, 20 3:33 pm  · 

prayer might work, if you worship the right deity

Apr 24, 20 5:25 pm  · 

It's hardness, find a tip harder than

Apr 24, 20 9:18 pm  · 
Wood Guy

Are you using metal-drilling bits? The shape of the tip and to some degree the flutes are different for different materials. Make sure the tip is sharp, but not a brad point as that only works for wood. 

As others have said, aluminum is soft; it can be cut easily with woodworking tools (just not brad point bits). Make sure the drill is set to "forward." (All lessons learned the hard way.) 

Apr 25, 20 9:18 am  · 

If you are using a cordless drill, try using a corded drill for your project.  They have a lot more power.

As others have said, the proper bit will help a lot too.  Also, a little drop of oil on the bit will help reduce friction and heat.

Apr 25, 20 11:03 am  · 

Every time this post gets necro'd by a spammer I think of the retro practice of drilling holes in bicycle components to reduce weight (many times aluminum components). I say "practice," but I should really say "art" as if done well, the results are simply beautiful (also if done too much the results are less functional). Google "drillium" if you're interested. You can even get some components straight from the factory replicating the style ...

Jul 9, 20 2:47 pm  · 
1  · 

Be careful that the aluminum does not overheat, I worked in a factory that made bleachers and the end of the 20' foot extrusions being cut into steps was still warped in paper and the heat from the saw was able to conduct down the aluminum and set the paper packing on fire, aluminum is a very good conductor of heat.

Always wear thick leather gloves when handling unfinished parts, drilling or cutting.

Over and OUT

Peter N

Jul 27, 20 1:58 pm  · 

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