UL under listing (KDER)Addresses Grounding and Bonding Equipment .
The catagorey covers bonding devices, ground clamps, and bonding bushings and locknuts, ground rods, armored grounding wire, protector grounding wire, grounding wedges, GROUND CLIPS FOR SECURING THE GROUND WIRE TO AN OUTLET BOX, watermeter shunts, and similar equipment.
UL nor other NRTL's list screws per say for the attachment of equipment grounding conductors to enclosures.
The following 2005 comment seems to indicate that CMP 5 accepts screws (other than coarse Thread SMS) all be it unlisted for this purpose
on Comment 5-40 only be reported as “Hold” consistent with Section
4-4.6.2.2 of the NFPA Regulations Governing Committee Projects. The
comment adds new material that has not had adequate public review. The
action on Proposal 5-57 stands as shown in the Report on Proposals.
Submitter: Frederic P. Hartwell, Hartwell Electrical Services, Inc.
Comment on Proposal No: 5-57
Recommendation: Accept the proposal in principle. Revise the last sentence
to read as follows:
“Where screws are used to make field connections of grounding conductors
or grounding terminals to enclosures, machine screws or thread-forming screws
with machine threads shall be used.”
Substantiation: The disallowance of sheet metal screws for this purpose is
appropriate, but the wording has raised three questions: what about metal-tometal
connections in listed enclosures, where the continuity has been evaluated
by the testing laboratory (presumably OK), and on field connections, what
about other screws, such as wood screws that are even less suitable than sheetmetal
screws? What about “teck” thread forming screws that result in machine
threads, but that are often referred to as a type of sheet metal screw? This
comment answers those questions. The real technical issue addressed in this
requirement is the poor mechanical advantage offered by a conventional sheet
metal screw with its very coarse threads. The submitter is aware that this comment
may need to be held in accordance with 4-4.6.2.2(a) of the Regulations,
but wanted to bring the issues to the attention of CMP 5.
Panel Meeting Action: Accept
Number Eligible to Vote: 16
Ballot Results: Affirmative:
