Interesting way to Nail a box to a wall stud... :)

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B4T

Senior Member
I have seen plenty of boxes installed with 10D nails going through it like some kind of ancient torture devise.. :lol:

But it does make it real easy to separate the box from the stud.. :thumbsup:
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Looks like an old box. A more modern box would have had the through holes in the back.
Gem%20box%20nails.jpg
 

ramsy

Roger Ruhle dba NoFixNoPay
Location
LA basin, CA
Occupation
Service Electrician 2020 NEC
I have seen plenty of boxes installed with 10D nails going through it like some kind of ancient torture devise.. :lol:
Encountered my first one last month, did not know what it was. Now I see it must be back east electricians bringing their right-coast wiring methods with them. ;)
 

renosteinke

Senior Member
Location
NE Arkansas
Yup, that used to be the 'normal' way it was done. That is why the NEC specifically forbids the use of screws 'inside' the box- fear the exposed threads would cut the insulation.
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
Yup, that used to be the 'normal' way it was done. That is why the NEC specifically forbids the use of screws 'inside' the box- fear the exposed threads would cut the insulation.

The NEC does not specifically forbid the use of screws inside of a box. You can use them if the threads are protected using approved means to avoid abrasion of the conductor insulation.

Approved just means the AHJ will allow it. That could be plastic tubing or a real good tape job, whatever the AHJ will allow.

If the screws pass through within 1/4 inch of the back and no threads are exposed, they would be compliant. Only exposed threads need to be protected.
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
Yeah but if one wire eat's up 2.25 cubic inches then those two nails should be good for a total of about 4.50 cubic inches of fill.

Actually, two 1/8 inch diameter nails would take up about 0.06 cubic inches, considering a 2 1/2 inch wide box.

The 2.25 cu. in. (for 12AWG) is the amount of free space required by 314.16(volume allowance), not the amount of space the wire takes up. Volume allowances don't apply to nails.
 

cowboyjwc

Moderator
Staff member
Location
Simi Valley, CA
Actually, two 1/8 inch diameter nails would take up about 0.06 cubic inches, considering a 2 1/2 inch wide box.

The 2.25 cu. in. (for 12AWG) is the amount of free space required by 314.16(volume allowance), not the amount of space the wire takes up. Volume allowances don't apply to nails.

I understand how it works, my point was that if a 3x2x2 box is 12 cubic inches and you have three wires and a device, I'm assuming there's a device, that doesn't leave much room.

And from which table did you get the 0.06 from?

Oh and no one is going to mention the missing KO seal?
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
I understand how it works, my point was that if a 3x2x2 box is 12 cubic inches and you have three wires and a device, I'm assuming there's a device, that doesn't leave much room.

And from which table did you get the 0.06 from?

Oh and no one is going to mention the missing KO seal?

For the boxes designed for the nails to go through them since they are so close to the back of the box they don't take up much room.

I didn't get the 0.06 from a table. I assumed a 1/8 inch diameter nail, 5 inches total length (2 nails, 2 1/2 inches each) and just did the math (V=H pi R squared). So .0625 sq = .0039062. That times pi = .0122654 and that times 5 = 0.061327

Edit - 0.06 isn't correct. I made an order of operations error. The correct answer should be 0.19257
 
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cowboyjwc

Moderator
Staff member
Location
Simi Valley, CA
For the boxes designed for the nails to go through them since they are so close to the back of the box they don't take up much room.

I didn't get the 0.06 from a table. I assumed a 1/8 inch diameter nail, 5 inches total length (2 nails, 2 1/2 inches each) and just did the math (V=H pi R squared). So .0625 sq = .0039062. That times pi = .0122654 and that times 5 = 0.061327

Edit - 0.06 isn't correct. I made an order of operations error. The correct answer should be 0.19257

ahhh haaa, I knew you were wrong.:p OK I didn't really know, but since I never am, you had to be.

OK I'll give you that those nails are farther back and not as big as they look in the picture.

And how did you use pi R squared when the nails are round?:dunce: It's pi R round, cake R square.
 

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
Over looking the fact, It looks "Hack" and there are open KO's, What code section would you call to fail the box being nailed like that?
 
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