S-5 Heater Coil Assembly, 103074-01

I'm fairly certain the threads, the two female 3/4" inlet/outlet, are "National Standard Free-Fitting Straight Mechanical Pipe Thread (NPSM)", and NOT the standard "National Pipe Thread (NPT)". I'm not a pro, but do plenty of DIY work. After purchasing this coil I went shopping for fittings, and I noticed every fitting had the same threading. So I figured it must be a standard threading. Once home, I noticed the threading on the plastic caps that come with the new coil visually looked much tighter than the adapter fittings I purchased. After going to another store, all the threads, again, were the same. So I went ahead and installed the adapters. I could tell by how difficult they were to thread into the coil that they were probably the wrong threading, but I had no other option. After finishing the installation, I had a small leak coming from both threads on the adapters. Luckily, if you can call it luck, the water here is incredibly hard, so the incredibly small leak will seal itself up in a few days. My hope is someone else reads this and is saves a bit of hassle.

Item worked out great, although it took 3 deliveries to get one that wasn't damaged.