314.5 Screws or Other Fasteners.
Code Change Summary: New code section on screws and fasteners used for boxes and other enclosures covered in Article 314.
In the 2023 NEC®, new Section 314.5 was added to ensure proper screws and fasteners are used where they enter the wiring compartment of an outlet box, device box, pull box, junction box, conduit bodies, fittings, and handhole enclosures.
New Section 314.5 is in Part I of Article 314 which applies generally rather than Part IV which would apply to manufacturer construction specifications and product standards. Not all boxes are required in the NEC® to be listed which is why this new code change is appropriately located in Part I instead of Part IV.
Even though there are several rules in new Section 314.5, the goal and intent of the new code section is singular; to protect conductors inside an enclosure from damage that can occur from using the wrong screws or fasteners. Sharp projections and exposed threads of screws run through enclosure covers or the sides of boxes can damage the conductors inside.
This new code section applies to screws or other fasteners installed in the field that enter wiring spaces and does not apply to those screws included as part of the listing and labeling of the box or other enclosure covered in Article 314.
During the second draft meetings NEMA submitted a public comment to delete the new language since it shouldn’t apply to fasteners entering enclosures that are included with the product and covered by the product listing. Code Panel 9 rejected NEMA’s proposal and clarified that the new code section does not apply to the manufacturers of boxes, and therefore does not accept the request to remove the new requirements.
Code panel 9 agreed that the wording in the new code language must clearly differentiate between screws provided in the field and screws provided by or specified by the manufacturer.
See the course image for a summary of the new code language in 314.5.
Note about the image: All screws in this image were supplied by the manufacturer with the enclosure and included in the listing of the enclosure. This code change applies when these screws are not present for some reason and the electrician provides other screws or fasteners in the field.
Below is a preview of the NEC®. See the actual NEC® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2023 NEC® edition of NFPA 70.
2020 Code Language:
This code section did not exist.
2023 Code Language:
N 314.5 Screws or Other Fasteners. 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 3⁄8 inch.
(4) Screws or other fasteners, other than in (3), penetrating a cover shall extend no more than 5⁄16 inch.
(5) Screws or other fasteners penetrating a wall of a box exceeding 100 in.3 shall extend no more than 1⁄4 inch, or more than 7⁄16 inch if located within 3⁄8 inch of an adjacent box wall.
(6) Screws or other fasteners penetrating the wall of a box not exceeding 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 body interior.
Exception to (3) through (6): A screw shall be permitted to be longer if the end of the screw is protected with an approved means.