🔩 DEWHEL Red Aluminum Weld-On Fitting Bung - 3/8" NPT Pipe Thread Pair Review

The product I received did not have a 3/8 NPT thread as advertised. My fitting won't even screw in halfway before it clicks into place. And yes, I'm pretty sure my fit is 3/8 NPT. measured the hole and it's a 5/8 straight thread, not an NPT!

Looked good as pictured but the 3/8 NPT threads were not cut deep enough to engage, except for one turn. I had to tap deeper on the steps to get deeper into the carving. It is not easy to hold a smooth round cork so as not to damage the finish. I had to sand and polish to get it clean. Apart from that everything is alright!

These plugs appear to be cast aluminum and not solid aluminum. I'm trying to weld one to an expansion tank I'm making for my car, I couldn't do it, every time I get a tow light to attach it throws a ton of dirt out of the connector and starts sharpening, never had one Problem with the others, which actually consist of round material (blank). It's absolute rubbish. Sizing and threading are good if anything, but without the option of welding I don't think it matters.