I hate to waste peoples time with what seems like a dumb question, but this one has been driving me nuts.

Are UL listed "yellow" insulated crimp connectors (Barrel connectors) an approved splicing method? The application is #10 THHN stranded in a 18x18x6 steel box. They were used to splice a couple of 30A feeders to some fans. The crimps are perfect, the wires are tight.

It's weird...wish I had a camera.