Die Cast vs. Steel Couplings and connectors 1

[jimioy]

I want to change some of our "Standard Work Practices". I want to ban all die cast fittings and use only steel. Can the argument be made that the steel fittings are better, and if so, how? I know they cost more, but if I can get better bonding results then I'm OK with that.

 

[resqcapt19]

With both types there is a large range in the quality. Assuming that they are both quality products, the only real difference is that the die cast will not take as much abuse (the fitting breaks) and it will fail earlier under fire conditions. I'm not sure that the last one makes any real difference because if the fire is hot enough to melt the fitting the insulation has already melted.
Don

 

[jimioy]

resqcapt19 - Thanks. Those are really the only things I could come up with, also - durability. What is your opinion of set screw vs. compression? Mine is that although I think set screw probably makes about as good a bond as compression and is a faster install, I prefer compression for the professional look it gives a facility. Thanks again.... Jimi

 

[BJC]

Set screw and compression fittings are both covered by ANSI and UL standards. Both will perform to minimum standards In my experience set screw connectors go in faster (especially if the crews are using cordless drills with nut drivers).
I have read and in my experience that set screw connectors are stronger. There is an artical somewhere on the Loma Pietra earthquake that finds set screw connectors held up better.
HAve you read NECA standard NECA-1-2000? It's a good place to start.

 

[resqcapt19]

Jimi,
I agree that the compression type make a better looking job, but I think that the set screw do just as good if not better job for the connection. For the best looking job you can use the indeter type, but I don't like them as far as meking a secure connection to the raceway. Here is a link to info on the interter type of EMT connectors.

http://www.hubbellonline.com/wiring/raco_bell/pdf/b8.pdf

Don

 

[RonShap]

I agree with what was said.
Although I saw a new type of fitting at a project the other day. It was made up of die cast set screw fittings with electrical tape on either side of the fitting
Of course they were trying to suck a pull string through the conduit and had too much leakage at the fittings. 10 years later, they never removed the tape so it looked dumb.

 

[waross]

Steel is stronger.
Some cheaper grades of Die cast have so little screw travel that if the joint is stressed to the point that the connector stretches slightly the screw can no longer be tightened. (The screw head hits the side of the connector before the end of the screw applies pressure to the tubing.
Bonding issues;
The Canadian code banned the indent type of connector decades ago because of chronic loss of ground integrity.
While still accepted by code, you may have bonding issues with stretched die cast connectors.