NEC 314.5 field installed screws

Jaybone812 said:
That enter wiring spaces , they are taking about screws you use to secure covers , like a 4” metal 1900 box blank cover , the 8-32’s will enter the wiring space so they have to be blunt ends , in no way does the language adress what you are saying, how can you consider the end of a screw you use to rigidly secure a box to a surface as entering the wiring space ?? It may enter for 1/2 a second when you secure the box but that’s not what the language or intent is adressing and the code making panels expect us in the field to actually have common sense and common sense says this rule has nothing to do with the point of the screw used to secure the box to a surface . If it did how would it be code compliant to mount regular 4” 1900 boxes to a surface unless they were bracketed ?? Think about it
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Yes i understand what the NECs intent was most likely such as avoiding sharp nails for covers to penetrate wiring inside cabinets. Thus screw length limits were provided for covers but this does not exclude nails that "enter wiring space" for cabinet securement.

Although i would not recommend nailing mounting screws after wiring installation it can and will be done
 
Jaybone812 said:
Screws or other fasteners installed in the field that enter wiring spaces shall be as provided by or specified by the manufacturer or shall comply with the following as applicable:
  1. Screws shall be machine type with blunt ends.
  2. Other fasteners shall have blunt ends.
  3. Screws attaching a cover shall extend no more than 10 mm (3/8 in.).
  4. Screws or other fasteners, other than in (3), penetrating a cover shall extend no more than 8 mm (5/16 in.).
  5. Screws or other fasteners penetrating a wall of a box exceeding 1650 cm3 (100 in.3) shall extend no more than 6 mm (1/4 in.), or more than 11 mm (7/16 in.) if located within 10 mm (3/8in.) of an adjacent box wall.
  6. Screws or other fasteners penetrating the wall of a box not exceeding 1650 cm3(100 in.3) and not covered in 314.23(B)(1) shall be made flush with the box interior.
  7. Screws or other fasteners penetrating the wall of a conduit body shall be made flush with the conduit bodyinterior.
Exception to (3) through (6): A screw shall be permitted to be longer if the end of the screw is protected with an approvedmeans.



These is the exact language of 314.5 common says tells me they are not referring to the end of the screw used to rigidly secure the box to a surface 🤷‍♂️
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1 and 2 of this code states screws with blunt ends and therefore to non sharp ended screws but not the screw head
 
Jpflex said:
1 and 2 of this code states screws with blunt ends and therefore to non sharp ended screws but not the screw head
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Then read 6&7 of this rule which should clear up any confusion you have , they refer to screws and nails listed in 314.23(b)(1) penetrating the wall of a box shall be made flush with box interior, right there it’s saying if you penetrate the wall of a box to secure it the head needs to be flush with the wall of the box or conduit body , idk man to me the rules language lines up with intent and looks like everyone else feels the same way , if you feels there’s a conflict submit a pi next codes and standards process
 
Jaybone812 said:
Then read 6&7 of this rule which should clear up any confusion you have , they refer to screws and nails listed in 314.23(b)(1) penetrating the wall of a box shall be made flush with box interior, right there it’s saying if you penetrate the wall of a box to secure it the head needs to be flush with the wall of the box or conduit body , idk man to me the rules language lines up with intent and looks like everyone else feels the same way , if you feels there’s a conflict submit a pi next codes and standards process
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Trying to memorize this book and finish the 2,000 pages front to back as best possible before testing but its like memoeizing a dam phone book.


I know its open book but i would really not want to fail
 
Jpflex said:
Plastic gang boxes come with manufacture supplied sharp metal wood nails. However, these are not inside the box nor penetrate inside the box. The nails are supported outside the boxes and "do not enter wiring space."
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This is the box i was thinking of.

Arlington | F101 Product Information

One Box® Non-Metallic outlet boxes. Single Gang. Vertical. 21.3 cu. in.
www.aifittings.com www.aifittings.com
 
Jpflex said:
Very good, i did not get to this code section yet, i just started this chapter. Does this imply that the interior scre head shall be flush with the box or no greater than 1/4" ?
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No but 314.23(b) is “structural mounting “ and (b)(1) is rules for “nails-screws “ used for structural mounting that’s why I said it should clear up confusion because for you thinking that 314.5 was addressing screws used to rigidly secure a box
 
To be fair to the OP, 314.5's reliance on the phrase "enter wiring spaces" to mean only screws/fasteners whose head is outside the wiring space is not terribly clear. It could be clearer, e.g. for screws only it could refer to "screws whose threads are inside the wiring space." Not sure how to phrase it more generally for other fasteners.

Cheers, Wayne
 
wwhitney said:
To be fair to the OP, 314.5's reliance on the phrase "enter wiring spaces" to mean only screws/fasteners whose head is outside the wiring space is not terribly clear. It could be clearer, e.g. for screws only it could refer to "screws whose threads are inside the wiring space." Not sure how to phrase it more generally for other fasteners.

Cheers, Wayne
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There are screws that enter the wiring space of the box and there are those that do not. This is dependent on the type of box used.
 
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