Rigid GRC Nipples

[c_picard]

Hey folks,

I feel like I may have gotten some bad intel as an apprentice...

GRC nipples from what I understand have tapered pipe threads, which work well with FS boxes and hubs, etc.,
but what about for connecting two boxes or enclosures without hubs? Regular locknuts never work, they don't thread on far enough. The few jobs where I worked with a lot of rigid we threaded all our own pipe, and I never had such a hard time getting locknuts on the field made sections of RMC.

What am I missing? The nipples we are getting from our supplier seem to be what you would find in the plumbing section of a hardware store, is this the same thread as a listed electrical fitting?

Thanks for any wisdom you could pass on.

 

[Smart $]

Hey folks,

I feel like I may have gotten some bad intel as an apprentice...

GRC nipples from what I understand have tapered pipe threads, which work well with FS boxes and hubs, etc.,
but what about for connecting two boxes or enclosures without hubs? Regular locknuts never work, they don't thread on far enough. The few jobs where I worked with a lot of rigid we threaded all our own pipe, and I never had such a hard time getting locknuts on the field made sections of RMC.

What am I missing? The nipples we are getting from our supplier seem to be what you would find in the plumbing section of a hardware store, is this the same thread as a listed electrical fitting?

Thanks for any wisdom you could pass on.

Rigid conduit threads are same as plumbers pipe ? NPT.

Have had the same situation. Yet a different box of locknuts worked fine... same make/part#.

If field cutting threads... cut deeper.

 

[stickboy1375]

Try a different batch of locknuts.... or re thread pipe.

 

[Cow]

Some locknuts just suck, make sure you're using actual rigid locknuts, and not just the leftovers shop stocked from a bunch of emt connectors.

Make sure the marks on the die line up to the pipe size, or even make it cut just a little deeper if you have too. When I'm taking rigid into a box or panel, etc using double locknuts I always cut the threads about a 1/4 to 1/2" longer than if I'm just running it into a coupling or hub. I like having a little adjustment in the locknuts to shift the panel around if I need too. Plus it gives you extra threads for the plastic bushing.

 

[c_picard]

Thanks for the input.

We get all our supplies from the same place, locknuts and all, must just be a bad mismatch.

They probably are leftover EMT locknuts!