Pipe Taps are used for threading holes created by a hole saw to receive a threaded pipe.To cut a hole for a 1"pipe tap,select a 1-1/8" hole saw.
Pipe Entrance is the diameter for the hole through which a pipe of a given diameter will pass during installation or repair.
Pipe Size is defined by the inside diameter.To cut a hole through which a 3/4"pipe may be passed,a 1-1/8" hole saw is used.
Tubing Size is defined by the outside diameter.To cut an entrance hole of a given tubing diameter,the same diameter hole saw should be used.