The pipe plug is a tapered thread, when it gets snug. it is good.
You don't want to hit it with a hammer, or try to tighten it till it is flush,pipe threads don't work that way.
a proper tapered thread should turn about 1 turn by hand then a wrench is needed.
usually being tight enough 1/2 or 3/4 ways in.
But it is a feel thing, if it feels tight than it is tight.
If one over tightens a tapered thread, they is always the chance of breaking the item it is threaded into.
Don't over think this.
