Thread tap acrylic

[Josh Kuper]

Any tips of threading a hole for studs in acrylic letters, 1/4" and 3/8" thick letters. We drill an undersized hole and use a tap from Home Depot that matches the stud thread, tried to tap by hand and use a drill softly but both methods seam to tear/splinter out the hold leaving the stud to barely hold in the hole

 

[brdesign]

You want to use a flat bottom tap to thread all the way to the bottom of the hole. Standard taps with the pointed tip will bottom out before they can start cutting threads in material that thin.

 

[ProSignTN]

Dip the studs in epoxy before screwing them into the letters.

 

[letterworks]

Or, if the letters are CNC cut along with the holes you might dial in a size to allow machine screws to act as a self tap.

 

[bowtievega]

Try a spiral tap for soft metal, that is what we use for aluminum and it works well for acrylic. Blind holes use a bottoming tap as said above which makes it a little tougher to start by hand since there isn't much taper. A drop of dish soap works well for lubrication. For a couple hundred bucks you can get a hand operated tapping machine, definitely recommend.

 

[Johnny Best]

I have used a drill press to set depth and straightness and made sure I am using the right size drill bit for my tap to go in without cracking acrylic.

 

[netsol]

I have used a drill press to set depth and straightness and made sure I am using the right size drill bit for my tap to go in without cracking acrylic.

i would think a drill press makes it much easier
would you use a tiny drop of some sort of soap, as a lubricant?
does it make sense to back off the tap, twice per revolution, to break up the shards?
with metals you program your cnc to do this, i have never done this with wood.
i would be skittish about stress cracks, WHICH WILL SPREAD

 

[Johnny Best]

Never used soap, just use the tap by hand with the tap in the holder, the important part is getting the perfect drill bit that matches the tap so as not to apply to much pressure on sides of drilled hole. Have never had a problem with cracking the acrylic.

 

[JWitkowski]

Tap drill chart used to select correct drill size to match your desired tap & bolt size, metric & imperial.

 

[netsol]

jwitkowski
we have those charts all over the shop as well...

 

[MikePro]

flat bottom tap or bust. you lose about 1/8"-3/16" of hole depth with those pointy-ones.