Best drill bits for PVC?
- Thread starter kibosh
- Start date
shado pilot
New Member
I've always used regular wood bits. Slow speed to prevent melting.
minieffects
Well-Known Member
They do make bits specifically for plastic. I personally use bits for metal. The key is to drill a pilot hole and work your way up. Another good tip is to use a unibit. You can get them in different sizes and they are perfect for drilling through sheet material cleanly. Also known as step bits.
Another tip is to use Kerosene as a coolent. It wont attack the plastic and it helps prevent overheating. This works for milling and lathing plastic as well.
Uni-bit / Step bit
http://www.tradetufftools.com/index.php?ma...CFRUFYgodeyrgog
Plastic drill bits
http://www.acrylicbirdcages.com/plastic_working_tools.htm
Good luck,
minieffects
Another tip is to use Kerosene as a coolent. It wont attack the plastic and it helps prevent overheating. This works for milling and lathing plastic as well.
Uni-bit / Step bit
http://www.tradetufftools.com/index.php?ma...CFRUFYgodeyrgog
Plastic drill bits
http://www.acrylicbirdcages.com/plastic_working_tools.htm
Good luck,
minieffects
Chris Martin
Well-Known Member
Slow speed for plastic. Similar to step drills are cone cutters which are essentially the same only conical rather than stepped (obviously). They continuously open the hole up rather than doing it in stages so if you need a hole with a diameter other than what the step drill allows, you can do it. The down side is that the edges are slighly angled rather than perpendicular.
kibosh
Sr Member
Well, I tried the step bits, but the PVC I'm drilling is too thick. I end up getting a larger hole than I wanted on the outside, and the inside gets the size I wanted.
I picked up some spade bits on sale at Home Depot. They worked pretty well. Instead of having a point, and then a flat cutting surface, the cutting surface points down at the ends. This scribes a line in the plastic before it actually cuts. This reduces the chipping.
An you guys are right. Slow and steady is the way to go.
I picked up some spade bits on sale at Home Depot. They worked pretty well. Instead of having a point, and then a flat cutting surface, the cutting surface points down at the ends. This scribes a line in the plastic before it actually cuts. This reduces the chipping.
An you guys are right. Slow and steady is the way to go.
minieffects
Well-Known Member
Yea if the plastic is too thick the step drills dont work so well. You did the right thing, I should have mentioned that. I have used paddle bits for the same application. If you can afford them, forstener bits work really well.
Here is some info
http://www.wisegeek.com/what-is-a-forstner-bit.htm
http://www.traditionalwoodworker.com/defau...p?cPath=269_270
all the best
minieffects
Here is some info
http://www.wisegeek.com/what-is-a-forstner-bit.htm
http://www.traditionalwoodworker.com/defau...p?cPath=269_270
all the best
minieffects
pennausamike
Sr Member
I would suggest 135degree split-point screw machine drill bits for holes up to 1/2 inch. They are self centering and because they are about half the length of standard jobbers length drills, they don't flex or walk all over the place. The 135 degree point is flatter than the standard 118 degree point which I like 'cause it goes down further before breaking thru. That's good on a drill press or mill, not quite as good by hand if you aren't used to it.
For bigger holes, a cheap hole saw set is nice and will work best if you "jog" the drill (bump the trigger rather than maintaining a steady speed) and blow out the chips a lot.
Mike
For bigger holes, a cheap hole saw set is nice and will work best if you "jog" the drill (bump the trigger rather than maintaining a steady speed) and blow out the chips a lot.
Mike
Jon Kelley
Active Member
Make sure they're sharp, run them fast, light pressure. If you can, back up the PVC with something stiff to keep it from getting cracked.
However, my best luck with plastic has been with "pyramid" or "step" bits - it saves you having to change bits as you progressively drill the hole, has one flute that clears easily, and it's a straight flute so it doesn't haul the plastic up as you first break through. Works on plastic, sheetmetal, or anything else rigid and thing (up to 1/4", depending on the progression of the bit.)
If you're going to do this a lot, it's worth going to the trouble to get one - or a set. Each one will do at least six or seven sizes. Check your hardware store, looking for "Uni-Bits" or similar. Also, you can order them from MRO houses - MSC Direct usually has good prices on stuff (anyone involved in fabrication should get their catalogue - it's free, hardbound, and about 4" thick - printed on onionskin...
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