I know that this is a REALLY OLD THREAD and all, but...in the off-chance that someone comes upon this and thinks that these switchcraft plugs are the bees knees...
I installed these on my electric rig around July of 2013. I installed male plugs on the ends of my cables for both the BK and HLT and installed female receptacles on the control panel and on small electrical boxes that connected to the vessels via weldless methodology (nut, o-ring, washer.)
Around May of 2014 the receptacle that was on my BK failed me during a boil, which was really frustrating. I think it was the contacts on the inside of the receptacle not contacting with the contacts on the male plug. I was wanting a way to remove the BK heating element for better cleaning anyway, so instead of replacing the receptacle with a new switchcraft receptacle I purchased a Brewhardware heating element enclosure with the soldered tri-clover thingy and got rid of the electrical box. Ugh! The nasty crap that was hiding behind that nut! If you have weldless connections on your boil kettle or mash tun, then it's a really good idea to remove them periodically and clean them thoroughly!
So this past weekend my HLT wasn't able to get up to temp, and I couldn't figure out why. I'd turn off the PID, unplug the cable, plug it back in, turn on the PID, and then it would work some more getting the temp higher, but it wouldn't get to my mash temps. Fearing once again that the receptacle failed me, I decided to bypass the male plug and female receptacle and wired the cord directly to the heating element and voila...it worked. I haven't fully investigated yet if the male plug malfunctioned or the female receptacle malfunctioned or maybe both. The crimp connections looked fine, so I'm pretty sure it wasn't that.
I'm now going to replace the HLT heating element connection with the same BrewHardware connection and am going to replace the switchcraft connectors with the more robust (and expensive) Neutrik PowerCon connectors.
These switchcraft plugs work, for a while. They never really do "lock" into place, though. Had to resort to other means to make sure that they stayed snugly connected to the control panel and vessels. I wouldn't ultimately recommend them.