Tower 1G Surface Box with 20mm knock out and mini knockout
Knock-outs can be tricky
Does the job, but some of the ones I used had knock-outs that refused to budge without cutting. The back can crack if you try to knock out without cutting.
31 May 2015
Surface box 20mm knock out
Used these to mount thermostats with cable glands in the knock out holes.
I pushed the knockouts from the outside and they broke away cleanly. It requires a fair bit of force.
Good price and fine for what I needed.
11 Dec 2014
Inexpensive and simple
For those having issues reliably removing the cut-out, this approach works for me every time...
Drill a central hole about the same diameter of your screwdriver, insert screwdriver, and lever to one side. The cutout should then come straight out cleanly.
3 Dec 2014
Ideal trunking to conduit box
Great box for connecting 20mm plastic conduit to plastic trunking. Only gave 4* on performance because the knockout didn't work for the 20 mm hole and had to be drilled. I box was badly broken because of this so beware.
26 Dec 2012