(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 3 of 3

Thread: Copper Types - K, L, M?

  1. #1
    DIY Member chetwynd's Avatar
    Join Date
    Jul 2005

    Smile Copper Types - K, L, M?


    I wanted to start a discussion about the three types of copper, to see what people use each of the types for. For example, what type do you use inside a house? What about underground? Do the fittings work on all types? Besides cost and ease of cutting, is there anything wrong with using a more heavy duty type?


  2. #2
    In the Trades Gary Swart's Avatar
    Join Date
    Sep 2004
    Yakima WA


    See the link on the home page of this site. Terry has a great summary of the various types of pipes. To summarize his summary on copper pipes, type M is the thin wall and is used for inside plumbing. Type L is thicker walled and is used for outside water service, and type K is the thickest walled and is used for water mains and meters. Fittings are universal.

    There would be nothing "wrong" about using a type L in the interior, but there is no advantage or benefit in doing so. Obviously as the thickness increases so does the price. Cutting requires more effort as the thickness increases, but tool used is the same, and I suspect it may take a bit more time to heat a joint to solder. Since the outside diameter of the three types remains the same, the inside diameters will decrease as the wall thickness increases, but it is such a small difference, you would not be able to tell by performance. Type M is more easily found, box stores always have it. To get the heavier weights you would probably have to go to a plumbing supply house.

  3. #3
    DIY Junior Member Climber's Avatar
    Join Date
    Jan 2006
    Columbus, Ohio


    Anything you ever wanted (or didn't care to) know about copper pipe is located in this pdf handbook:


    A great resource!


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts