Copper Pipes

The difference is wall thickness and each can be obtained in soft or hard tempers for different applications. The outside diameter of standard copper tubing sizes is the same for all 3 types but the wall thickness varies with M having the thinnest wall, then L, then K with the thickest wall.

See www.copper.org the website of the Copper Development Association (CDA) for additional information and application guidelines.

thanks bluestone. That's help a lot.