Rod Couplings

[Alwayslearningelec]

So I'd thinking rod couplings(for trapeze conduit racks) would rarely be needed. If you buy 10-12' lengths and you lengths are also less then that you wouldn't need them? But I guess if you need 7' lengths and you want to use the remaining lengths(and not waste) you would couple the 3 or 5' remaining length? Not sure that's how it would work.

 

[BillyMac59]

Ever suspend something from a 40' ceiling like in a factory? Rod couplings are often used.

 

[Alwayslearningelec]

Ever suspend something from a 40' ceiling like in a factory? Rod couplings are often used.

No. But I get it. So if the rod drop lengths exceeds the lengths of rod you bought then rod couplings are obviosly needed?

 

[BillyMac59]

Exactly. Most places I've worked would stock 3/8" rod in ten foot lengths as well as a box of couplings.

 

[LarryFine]

Not sure that's how it would work.

Think about it just like conduit. What do you do when you need longer or shorter than a 10ft length?

If you need longer, you use one or more couplings; if you need shorter, you cut the length you need.

Often, you end up with one or more full lengths plus a last piece cut to length, just like with conduit.

 

[Alwayslearningelec]

Think about it just like conduit. What do you do when you need longer or shorter than a 10ft length?

If you need longer, you use one or more couplings; if you need shorter, you cut the length you need.

Often, you end up with one or more full lengths plus a last piece cut to length, just like with conduit.

Thank you. I would think most of the time your rod drops from the ceiling are less than 12 or 10 ft so if you have those length you just cut it short and no coupling.

 

[infinity]

Thank you. I would think most of the time your rod drops from the ceiling are less than 12 or 10 ft so if you have those length you just cut it short and no coupling.

If possible I would use a rod length that avoids the coupling. It's just more parts and labor that you can avoid by using longer than the standard 6' threaded rod.

 

[LarryFine]

I would think most of the time your rod drops from the ceiling are less than 12 or 10 ft so if you have those length you just cut it short and no coupling.

Exactamundo. Shop for materials most suited for the individual job.

 

[Eddie702]

You also want to keep the waste down. But the waste is somewhat offset by the increased cost of labor to install extra couplings.

If you know the lengths, you need before buying the rod, lets say your hanging at 14 or 15'. You could use a 10' and a 6' and have a foot or two of waste. If you buy all 10' rods you would have 5 or 6' of waste.

If you have a guy on the ground assembling the rods and one guy hanging the rods even with couplings I don't see much labor increase.

 

[garbo]

I worked in a large maintenance shop . They only purchased 6' lengths of all thread but we had 10' lengths of 3/8,1/2 & 3/4" forget if it was called hot or cold rolled steel round stock ( black in color ) . We had the necessary machine thread dies for one of the powered Rigid pipe threading machines with threading oil to make long sections of threaded rod. A couple of times they ordered 20' lengths for jobs. Best thing with making your own long threaded rods we easily able to bend it to clear large duct work at ceilings to hang unistrut or overhead conveyors. We were taught to always use a hex jam nut at all all thread couplings to prevent them from coming loose.

 

[LarryFine]

If you know the lengths, you need before buying the rod, lets say your hanging at 14 or 15'. You could use a 10' and a 6' and have a foot or two of waste. If you buy all 10' rods you would have 5 or 6' of waste.

I would use 1-1/2 10' rods (15') per hanger, with little to no waste.

 

[Eddie702]

I agree with the need for jamb nuts. But I was told an interesting story by someone in the know who told me " lets say you put an anchor in the ceiling and screw in a rod with a jamb nut. When you tighten the jamb mut you are reducing the rods strength."

lets say the rod is rated to hold 800# and the anchor has a 3000# pull out. You tighten the jamb nut which now reduces the rods carrying capacity and the anchors pull out strength

Just saying. not saying I agree 100%

 

[augie47]

I always used jam nuts on the rod couplings and elastic stop nuts on the bottom of the strut.
Probably overkill but I liked the "security"

 

[Article 90.1]

Back in my day.... We used to use rod couplings in a socket to tighten hex shaped lugs. The only Allen wrenches people had on them were the metal Klein sets. If you were working in an I-Line panel that had 1/2" lugs, a rod coupling often worked better. Now we just walk into the box store any buy all the wrenches you need. Back then it was Klein at the supply house and Sears for Craftsmen wrenches.