can't remove knock out

[PoorOwner]

Have you guys run into this? I never had problem with electrical boxes but got this outdoor nema 3R receptacle box, on the side that I need to put a fitting, the circular cuts are made not deep enough. All the other KOs are fine, as is the one I installed in another location.

Since it is a concentric 3 size one the largest size started to move a bit, I don't have KO cutters or anything like that. I think I need to return it.

 

[Pingel85]

Sometimes the tack weld in concentric kos get a little agressive. If you can't return use a Meyers hub and reducing bushing.

 

[PoorOwner]

It was almost like the metal was barely cut.

 

[DieselNut88]

Some can be hard to remove especially when installed. I use a large flat screwdriver and a hammer or my linesmans. Dont be afraid to use some force. The larger boxes tend to be harder.

 

[Bert_]

There's only two possibilities with these knockouts. Either they are barely stamped and hard to remove or they all fall out with a light tap, leaving you with a hole a couple sizes to big.

In all seriousness get a hammer and a sharp chisel sometimes helps. Have a few reducing washers ready because you might knock loose more knockouts then you want.

 

[Norcal]

If the die that they stamped out the KO's with was that dull and no access to KO punches, use the appropriate size hole saw, another option is if a larger size KO breaks out use reducing washers.

 

[PoorOwner]

Here is a picture

 

[John T]

oh for hells sake...

 

[zmaxmotorsports]

Have you tried flipping box over and hitting it from the other side?

 

[mm08822]

Place box on wood to support all rings and hit inner ring on edge opposite its attachment point with screwdriver blade. Work the break towards the attachment point and then use linemans or dikes to break final portion free.

 

[Ole Slewfoot]

Hammer first, Unibit if it doesn't work.

 

[Evan(CA)]

I <3 my M18 Forcelogic knockout kit. It's easily become my favorite tool and worth every penny of it's steep price.

 

[PoorOwner]

I checked the back and it become obvious why it would not work, it's held in 3 spots. I need to drill those out and clean up with unibit.

 

[James-W]

I checked the back and it become obvious why it would not work, it's held in 3 spots. I need to drill those out and clean up with unibit.

I agree, if you can't knock it out then drill it out.

 

[Marctrees]

For the tough KO's, end grain of a 2x4 standing up like an anvil, right up agaiinst backside of where you are striking, hammer and old wood chisel at an angle at the first and second "3 points".

Marc

 

[PoorOwner]

Thanks everyone. After drilling small holes was able to remove and finish with unibit.

 

[matt_i]

If its a 3R (raintight) then I don't think its supposed to leak if you didn't use the knockout. So they probably purposefully left it shallow.

I've posted this before but if you are looking for some new tools, Hougen Hol-Cutters and Blaircutters will make short work of this problem, clean burr-free holes.

 

[Bert_]

If its a 3R (raintight) then I don't think its supposed to leak if you didn't use the knockout. So they probably purposefully left it shallow.

I've posted this before but if you are looking for some new tools, Hougen Hol-Cutters and Blaircutters will make short work of this problem, clean burr-free holes.

A knockout on 3R boxes is never designed to be watertight. The knockouts are located in the bottom or in the side below any gear inside. So water getting in though these holes is not an issue, it will just drain back out without causing problems.

If the you put a hole in the side above the gear inside, then you need to use a sealing locknut or a meyers hub to keep water out.

 

[PoorOwner]

Yes Bert is right, the receptacle and switch would not be affected when a little bit of water or condensation goes in from there, the box is made in a way so water should not enter from the top and there is drainage hole on the bottom. The other KOs work correctly, I can see a little light through them.