Quote Originally Posted by kd8dey View Post
Copper comes in three grades, M for thin wall pipe used mainly inside homes, L for thicker wall pipe, used mainly outside for water services and K, the thickest, used mainly between water mains and the water meter.
OK, thanks! The last time I looked at the price of copper pipe at either Lowes or Home Despot I about had a heart attack. No idea what grade it was though, just the stuff in the rack in the plumbing section.