What acrylic drill bits do you use?

5dice

Arachnopeon
Joined
Sep 10, 2016
Messages
14
For thin plastics I use a hot nail as it leaves nice, smooth holes when compared with a drill bit. But I want to drill into acrylic. Will any old plastic bit do? What about stepped bits?
 
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Red Eunice

Arachnodemon
Joined
Mar 2, 2014
Messages
667
For thin plastics I use a hot nail as it leaves nice, smooth holes when compared with a drill bit. But I want to drill into acrylic. Will any old plastic bit do? What about stepped bits?
The odor of melting plastic is nauseating to me. I prefer using the Dremel on thin plastics.
Acrylic drilling is done on the drill press using 165° bits @ 2200 rpm. Light pressure, drill slow = clean holes with no cracks or chipping.
Never used step bits, primary use is for metal, could work though. Cracking might be a concern as would be excessive chipping.
I have used brad point bits and they give good results but correct pressure is of the utmost importance.
Drill bits, like saw blades, the more cutting teeth the smoother the results. :);)
Should add my favorite bits are 3 flute design and come in but a handful of sizes. The local commercial HVAC supply company carries the size I use most often 3/16".
 
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sdsnybny

Arachnogeek
Arachnosupporter
Joined
Apr 29, 2015
Messages
1,331
Tap Plastics sells acrylic specific bits and they work very well. The fluting on them as well as the angle of the bit grind is different than wood or metal bits. I have not had any difficulty with the ones I purchased.
 

Formerphobe

Arachnoking
Joined
Feb 27, 2011
Messages
2,342
I just use standard bits with a high speed hand held drill. I've never had any melting, cracking, splitting, etc. Let the weight of the drill carry the bit through. Too much pressure will cause breakage.
 

viper69

ArachnoGod
Old Timer
Joined
Dec 8, 2006
Messages
11,508
I get perfectly smooth holes using drill bits. I've drilled through those thin beta cups from pet stores, perfectly smooth. I've never used heat as a means of making holes for T containers.

I use standard bits myself. Though TAPS sells acrylic bits that are single fluted unlike normal drill bits, and their angle is different as SDS mentioned above. They are significantly more money. I cannot say if they will work better than standard bits that I use.

TAPS plastics says you know you have drilled acrylic properly when you see a single piece of plastic come off the bit. I have done this a few times w/a drill press using standard bits.

Dremel typically spins bits at too high RPMs. The average user ends up melting the plastic actually, though the hole itself may look fine or not for some.

The key is not to press into the acrylic, let the bit do the cutting. Also, it may help some if you put a wooden block below the actual acrylic you are drilling to prevent it from flexing. I haven't had to do this, but I follow the method of "slow and sure".
Acrylic cracks VERY easily if you drill too fast.
 

Spidermolt

Arachnoknight
Joined
May 29, 2015
Messages
203
I've used wood and metal bits before and noticed that the metal bits caused a lot more chipping and a slight higher chance of completely cracking the whole acrylic, the wood bits always leave a nice clean hole.
 
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