[pastor1189]

Either a steel nipple or plastic how do you drive the nipple into a hollow smooth pipe.
Threads on both ends . Main purpose is thenipple with threads stick out of the pipe's end perhaps a 1 inch. So a slip nut could be turn on the nipple. Do you just pound the nipple
Down the hollow pipe, or should you pound a threaded bushing down the pipe first?

Your views

[ma0641]

You don't pound it. You get a threaded adapter that glues in or on the smooth pipe and then thread the nipple into it. What is this pipe and diameter?

[pastor1189]

Caliper reads 100 outside dia. Inside 0.18

[ma0641]

You didn't tell me the material of the pipe. Is it metal or plastic. "Caliper reads 100 outside dia. Inside 0.18. 100 what? Millimeters? 1.00 inch? Based on your picture, I don't think your measurements are correct. Inside would be close to 100 or 1.00 inches too. 0.18 wall thickness perhaps?

[pastor1189]

I will just bring the pipe to the store. Like you said threaded adapter,
Other type is insert nut. Both have threads you can screw a nipple
Thanks appreciate it