This discussion began on another thread
http://forums.mikeholt.com/showthread.php?t=87011
iwire said:
David, for lack of a better way of putting it.....this is nuts.
There is no NEC prohibition against using drywall screws to mount equipment, there is no NEC requirement that the mounting hardware be listed for the purpose.
I think you are out in left field.
dnem said:
Yes, ASTM C 954 for Type S-12 for steel stud drywall screw applications
ASTM C 1002 for Types G, W, + S for wood stud drywall screw applications
Those are not listings or codes, they are simply standards that have voluntary compliance.
You?re way off base Bob !
?There is no NEC prohibition against using drywall screws to mount equipment,?
True, but it?s not the
equipment that is restricted. . You failed to read or ignored the post directly in front of yours. . In it I said, ?I don?t think you?ll find any screws listed
exclusively for any particular application but you can find restrictions.? . 110.3(B) isn?t either
for or
against any equipment. . 110.3(B) isn?t
for any particular or exclusive purpose or application. . But 110.3(B) is
against (as in: prohibits) certain applications. . It?s against applications that violate the listing requirements.
The drywall screw restriction isn?t about equipment, it?s about any application that puts the screw in a position to need to withstand X amount of sheer force. . There are also different categories of sheer force. . Sheer force that is applied thru a soft or pliable material (such as wood or drywall), is not transferred directly and completely to the screw. . Sheer force that is applied thru a hard material (such as steel), is transferred directly and completely to the screw. . When the panel rested directly on the screw head, or neck of the screw head, any blunt shock force from the metal being struck is transferred directly to the screw head.
?there is no NEC requirement that the mounting hardware be listed for the purpose.?
That?s definitely not true ! . That?s exactly what 110.3(B) is saying. . There is no NEC requirement that the mounting hardware be listed for specific equipment. . There most definitely is a NEC 110.3(B) requirement that the mounting hardware be listed for the purpose or application.
Another example would be an anchor that is tested and listed as being able to hold X amount of weight. . The listing doesn?t restrict the specific type or category of equipment that can held by that anchor but the weight restriction is still valid for
all equipment. . The purpose or application carries a listing restriction.
?Those are not listings or codes, they are simply standards that have voluntary compliance.?
Listing is commonly based on established standards that are backed by testing. . What other information would you use to determine the limits of a listing ? . Bob, do you think UL just guesses ? . During a tour of our local CSA testing lab, they stated that they follow UL standards for their testing. . CSA is a competitor of UL and yet the standards are still respected and used by them. . ASTM is another group of standards that was mentioned by the CSA rep.
David