Straps for EMT (one- or two-hole)

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lordofpi

lordofpi

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New Jersey
Trivial topic, but since EMT seems to be the topic/flavor of the week here, what fitting do you all use for securing/support? Hangers have their own place, but how about 1 versus 2 hole straps? 1-holes always seem to be stronger, plus save time. Thoughts?
 
Depends on the size. Up to 1-1/4", I like one-hole. Bigger than that, two-hole. Depends on what the application is, mainly. Not much bigger than 3/4" would I normally run tight on the surface anyhow.
 
What type of fastner do you all like to use to secure the strap to the surface? Is there even anything in the code related to it? Would a drywall screw be acceptable?
 
Having seen the two hole straps I've seen, it seems that the one hole straps are thicker metal.
However the engineering analysis would show that, due to leverage, it is possible to physically wrest a piece of conduit secured with a one hole strap away from the wall. But a two hole strap would resist this force from any direction.
Therefore, 2 hole straps are inherently more secure.
~Peter
 
Having seen the mfg video on propper strap use the one hole is designed to be hung from the top not from the bottom and this sometimes freaks out electricians who have been doing it the wrong way for years. Kevlar underwear installed now.
 
quogueelectric said:
Having seen the mfg video on propper strap use the one hole is designed to be hung from the top not from the bottom and this sometimes freaks out electricians who have been doing it the wrong way for years.
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This is one for the "learn something new every day" department. Count me among the electricians who have been doing it wrong for years.
 
I definitely have been doing it the wrong way as well. The one-holes just seem not to curl around enough to support the raceway from the bottom, so I always assumed the other way was better. This explains why I've occasionally had bent straps from this (the strap bends back away from the the wall, removing the tight fit).

Malleable iron straps were mentioned; has anyone any experience with these? I would imagine they would be superior, but I'm not sure. I'd hate to order on a guess. Also, what manufacturers do you all prefer? We all know that Halex is the best :roll: -- but I'm sure everyone has their favorites that come close.

Incidentally, I used to use 1 5/8" drywall screws (wood screws just always seemed like a poor design) till I found out just how prone to sheering they are. Now I use 1 5/8" decking screws; they're less brittle, more corrosion resistant, and less prone to cam-out. I drive them with a T25 TORX bit. If only I could find them painted white instead of tan and green. It is a bit of overkill, but that's my good old OCD kicking in again ;).
 
quogueelectric said:
Having seen the mfg video on propper strap use the one hole is designed to be hung from the top not from the bottom and this sometimes freaks out electricians who have been doing it the wrong way for years. Kevlar underwear installed now.
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Looking @ a box of one holes,there is no right or wrong to install,if mfg have videos they should provide directions for proper use of their products.I think the anchoring system plays a big role in the performance of the straps whether it is 1-or -2-hole.I will continue to support 1-holes form the bottom unless I see direction otherwise,I have seen 1-holes supported from the top open up and release the conduit...
 
I kind of go along with what Marc said, kind of depends on the size of the pipe.

which way I hang the strap also depends on how much I'm trying to hide the pipe. If I'm really trying to tuck it up under the eaves and don't really want to see it I'll support it from the eaves or from the top if I'm trying to hide the straps, but I ususally put the holes down.
 
480sparky said:
Use minnies then.
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I thought our topic was what do we use for surface mounting conduit, which I took to mean flush with the surface, minis stand the conduit off the surface, and while we are on the subject, I do use minis when I think they are appropriate...:)
 
i like you guys to use the one-hole straps...

i like you guys to use the one-hole straps...

because it is easier for my low-voltage guys to get their tie-wraps around your EMT when they are following you around the job site.
 
jrdsg said:
because it is easier for my low-voltage guys to get their tie-wraps around your EMT when they are following you around the job site.
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you sure you dont mean minis? one hole straps hug tight to the wall.
 
I like 1-holes and place the screw above the conduit on horizontal runs. Putting the screw under the pipe gives the weight of the conduit leverage to pull the fastener out, whereas with the screw above, it just hangs.
 
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