4 11/16" box

[domnic]

Where and why did they come up with that size box . 4 11/16" ?????????????????????????????????????????????????????????????????????????????

 

[LarryFine]

I can only guess that it's based on a bending space allowance or a conduit entry size.

 

[drcampbell]

120 mm

 

[letgomywago]

I've seen some crazy old odd metal boxes. I wonder how many different sizes were tried in history.

 

[electrofelon]

120 mm

It's closer to 119 mm. Very close, about 2.5 thousands of an inch . But do you have any evidence that it is based on a metric size?

 

[letgomywago]

So no actual proof but I was told that it was the size of the inside of a type of I-beam idk if that was ever the case though or true.

 

[infinity]

While we're guessing, it the maximum width that you can have for each box when installing three boxes between two studs that are 16" on center.

And yes I just made that up.

 

[tom baker]

Not likely metric based, The 4 11/16 was around long before the NRC added metric dimensions

 

[OldBroadcastTech]

Just a S W A G........but perhaps the best size to allow 2 x 3/4" + 1 x 1 " OR 2 x 1" + 1 x 3/4" conduits per side ?

 

[drcampbell]

So no actual proof but I was told that it was the size of the inside of a type of I-beam idk if that was ever the case though or true.

Doubtful. A myriad of sizes are available.

http://www.coyotesteel.com/assets/img/PDFs/databook.pdf

This is just the first page:

 

[garbo]

Where and why did they come up with that size box . 4 11/16" ?????????????????????????????????????????????????????????????????????????????

Side note on 4 11/16" Boxes: I installed a few of them in my garage feed from 3 4" EMT years ago. Last year I wanted to install double duplex receptacles in two of them in case I wanted to plug a portable table saw or something else into. Neither of the big box stores or my local supply house had covers in stock so glad I was sitting down when I checked prices thru Amazon & other site. One place wanted almost $15 for a 4 11/16" double decora cover that I was going to use for a GFCI Decora receptacles. Was lucky enough to find a 4 11/16" to a 1900 box mud ring in my PLO ( YEP parts left over ) pile. so went with that.

 

[LarryFine]

How about these with 2g plates? $4.46 @hd.

 

[darekelec]

I heard somewhere that it’s the maximum width that you can have for each box when installing three boxes between two studs that are 16" on center.

 

[LarryFine]

I heard somewhere that it’s the maximum width that you can have for each box when installing three boxes between two studs that are 16" on center.

If that's true, it originated back when 2x4s were fully 2" x 4", because 3 x 4-11/16" (4.6875") = 14.0625".

 

[letgomywago]

If that's true, it originated back when 2x4s were fully 2" x 4", because 3 x 4-11/16" (4.6875") = 14.0625".

Also would need flush covers. When did mulberry start making those?