Bicycle frame tube .. What are these joints called please

[Noods]

Where you get two sections of tube joining each other like those on bicycle and some motorcycle frames, can someone advise what this joint is called and how it made perhaps.. It's the one where a half round is cut out of the end of one tube for it to mate with the other...

Thank you ..

 

[pedrobedro]

Try this thread.

 

[Noods]

Try this thread.

Your a good man thank you Muchly so ...