Have seen on the Forum different concerns between Nylon vice Brass Plugs. I fouled the threads on my tank drain and can't get the OME plug to thread, however, I went to a RV Parts place and specifically asked for a plug for my model number Atwood W/H. The lady checked her parts list and came back with a CAMCO brass plug with a petcock. The brass plug will catch and snug down. While camping this past week, I came across a guy with a brass plug in a Atwood W/H that he has used for years with no problems. So, what to do? I'm leaning toward the brass plug.