Air Compressor Lines

[jenkinsph]

Here is more information than you want to know about copper pipe. It does identify Type M as suitable for compressed air. And it talks about the effect of different solders on the pressure rating for the pipe and temperature vs. pressure rating. And a lot more:

http://www.copper.org/publications/pub_list/pdf/copper_tube_handbook.pdf

Sorry, I don't use Type M for anything worth doing. The labor is the same for installation and the L hard is a more durable product.