Did you put it in with a 1/2 breaker bar or 3/4 impact? laugh2

That is literally the first NGK plug I have ever seen do that.

It might be a issue with that particular plug number but If you do that with a NGK automotive plug I think you dont know your own strength.

67 Barracuda street/bracket car 11.27-119
68 Dart 502 BB 8.70s-152
414 cid SB Dragster 7.65-174