Same o.d., same fittings, you won't notice a difference in flow from the change in i.d. Answer from Shmeepsheep on reddit.com
Family Handyman
familyhandyman.com › home › skills › plumbing › pipes
Differences Between Type L and Type M Copper Pipes
September 10, 2025 - But for normal in-wall household plumbing, Type M works fine. When it comes to copper piping for water lines, acidic water with a pH of seven or less can be hard on copper pipes. If you have a well and find out from testing that the water is acidic, you may want to use the thicker-wall Type L pipe or plastic CPVC pipe and fittings.
Manibhadra Fittings
manibhadrafittings.com › home › copper nickel fittings › type astm b 88 3, l vs. type m copper pipes: what’s the absolute top difference?
Type ASTM B 88 3, L vs. Type M Copper Pipes: What's the absolute top Difference? - Manibhadra Fittings
December 11, 2025 - As a result, type l needs more copper to produce, resulting in a higher production cost than type M. Since type L weighs more than type M, the cost of transportation is also higher.
Videos
Reddit
reddit.com › r/plumbing › type l vs m copper pipe?
r/Plumbing on Reddit: Type L vs M copper pipe?
September 22, 2021 -
Im swapping out original copper water lines with new copper while I already have a few walls opens. I haven’t cut into the old lines yet to determine whether it’s type M or L and there isn’t printing on the pipes indicating it, but the question is this. If I upgrade what I currently have access to, to type L for longevity purposes, am I going to have issues with flow restriction? Any issues with mixing in type L if the original is type M?
Westlake Ace Hardware
westlakehardware.com › home › what do the letters ‘k,’ ‘l’ and ‘m’ on copper tubing mean?
What do the letters 'K,' 'L' and 'M' on copper tubing mean? - Westlake Ace Hardware
October 13, 2020 - Type K is the heaviest. Type L is medium weight and used most often for water lines in homes. Type M is thinner and is used underground or for light
Bob Vila
bobvila.com › interior › plumbing › the differences between copper pipe types, explained
4 Copper Pipe Types: What is the Difference? - Bob Vila
July 28, 2020 - If a home is known to have water issues like hard water, Type L copper is often the go-to choice because hard water will not wear through the thicker walls as easily as they will through Type M pipe.
DoItYourself.com
doityourself.com › doityourself.com community forums › heating, cooling, air conditioning, ventilation and t-stat controls › boilers - home heating steam and hot water systems › type l or m copper pipe?
Type L or M copper pipe? - DoItYourself.com Community Forums
January 11, 2011 - Copper 90-Degree Cup x Cup Pressure Elbow - C607 at The Home Depot x25 NIBCO 3/4 in. Copper Pressure Slip Coupling - C601 at The Home Depot Flux, solder, emery, b tank. Lets say $400. Labor??? Pex probably install 1/2 the time of copper and less joints. You will still have to solder pex adapters on the heat elements but could probably just use a map gas hand held torch.
Whittinspections
whittinspections.com › home › explaining the differences between copper pipe types
Types of Copper Pipes: A Homeowner's Guide To Fix It Yourself
May 8, 2022 - Plus, they won’t break the bank! They typically last longer than Type M pipes, even if you have acidic or hard water. ... Of the common copper pipes, Type K one is the densest, with about a 0.065-inch thickness on a 3/4″ pipe.
The Spruce
thespruce.com › types-of-copper-piping-844852
4 Different Types of Copper Pipe and How to Choose One
November 10, 2025 - Copper pipes serve as the backbone for home plumbing systems, providing corrosion resistance, reliable connections, and lasting up to 70 years. Among the four prevalent types—Type K, Type L, Type M, and DWV—each has specific characteristics that make them suitable for different applications.
PlumbingSupply.com
plumbingsupply.com › home › categories › pipe & tubing
High-Quality Copper Pipe - Type L and M Options
Purchase rigid type M copper pipe and type L copper piping. Available in 1/2", 3/4", 1", 1-1/2", 1-1/4", 2", 2-1/2", 3" and 4" nominal sizes
Quora
quora.com › Should-I-use-a-type-L-or-type-M-copper-pipe
Should I use a type L or type M copper pipe? - Quora
Type L is more stronger than Type M as there is difference in thickness of pipe. Type L is generally used for underground, water heating systems and for commercial purpose. On the other hand Type M is generally use...
Reddit
reddit.com › r/plumbing › type m, l or k?
r/Plumbing on Reddit: type M, L or K?
April 1, 2017 -
If I'm trying to do the best job possible, which type of copper pipe do you all use regularly? is type M too thin for most applications? is type K prohibitively expensive, hard to work with or just unnecessary for general applications? is type L the Goldilocks of copper pipe or do I have it all wrong? I'm gonna do a short 3/4" run under a house and then some 1/2" for toilet and shower supply lines. What should I use? not concerned with price as much as I am with doing a good job. Thanks all for your time and input, this sub has been a wealth of knowledge
Reddit
reddit.com › r/plumbing › plumber promised l-copper pipes and is now "probably" using m-copper pipe. is this a fight i can win?
Plumber promised L-copper pipes and is now "Probably" using M-copper pipe. Is this a fight I can win? : r/Plumbing
January 7, 2023 - It's up to code to use M inside a house and it's also perfectly fine and you won't notice anything different. However Type M is a cheaper pipe due to being less actual copper so if he's trying to say that he used all type L to charge you more than he is lieing because the other comment is correct ...
Wikipedia
en.wikipedia.org › wiki › Copper_tubing
Copper tubing - Wikipedia
4 days ago - Common wall-thicknesses of copper tubing in the U.S., Canada and India are "Type K", "Type L", "Type M", and "Type DWV": Type K has the thickest wall section of the three types of pressure rated tubing and is commonly used for deep underground burial, such as under sidewalks and streets, with a suitable corrosion protection coating or continuous polyethylene sleeve as required by the plumbing code. In the United States, it usually has green-colored printing. This pipe designation is used in the Refrigeration Industry.
LinkedIn
linkedin.com › pulse › most-common-types-copper-tube-klm-eric-wang
The Most Common Types of Copper Tube: K/L/M
February 4, 2020 - The actual outside diameter (OD) of rigid copper type is always 1/8 inch larger than the nominal size, or what the pipe is called. For example, a "1/2-inch" copper pipe has an outside diameter of 5/8 inch. It is true with all three common types of new pipe, K, L, and M.
Reddit
reddit.com › r/askaplumber › do i have type m or l copper?
r/askaplumber on Reddit: Do I have Type M or L copper?
June 23, 2024 -
The copper on the left is a 1/2 cut out I have from a new angle stop install. The copper on the right is 2’ stick of Type M copper I bought from Home Depot a few months ago. The cooper on the left looks much thicker, however, I took my cut out (on the left) into Home Depot to compare to actual Type L and it looks thinner and closer to the Type M on the shelf. Do I have Type L with some wear of the inner walls (it’s an old house) or do you think I have Type M but the piece I bought on the right is just extremely thin? Thank you!
PexUniverse
pexuniverse.com › copper-pipe
Copper Pipe, L & M types - Sold by Ft - PexUniverse
Nominal/CTS size is used to designate all common copper pipe used in plumbing (type L) and heating (type M) applications. The actual OD of a copper pipe is always 1/8" larger than CTS size. 3/4" nominal copper pipe would have 3/4" + 1/8" = 7/8" OD; ...
DIY Home Improvement
diychatroom.com › home › forums › home improvement › plumbing
Type L or M copper | DIY Home Improvement Forum
The difference is thickness of the wall of the pipe. You should check local codes to make sure there is no special requirement in your area. Subject to the code, if your water is non-corrosive you can get by with M--the thinest wall.
Quora
quora.com › What-is-the-difference-between-type-L-and-M-copper-pipe-What-are-the-best-applications-for-each
What is the difference between type L and M copper pipe? What are the best applications for each? - Quora
Answer (1 of 3): Type L has a thicker wall than Type M. Type K has the thickest wall of the standard copper pipe types. In our company, Type M can be used for interior plumbing not exposed to freezing temperatures at anytime of the year.
The Garage Journal
garagejournal.com › forums › the tools › general tool discussion
L or M copper pipe for air lines? | The Garage Journal
September 12, 2012 - If you want to use copper, I would get the heaviest wall I could. OD of k,l,m is all the same, they use the same size fittings. ID is the one that is different, but it is such a small difference that it won't make any difference. You can always go up one size of pipe, from 1/2" to 3/4" if you ...
Hunker
hunker.com › 13417098 › what-is-the-difference-between-type-m-l-copper-pipe
What Is The Difference Between Type M & L Copper Pipe? - Hunker
December 7, 2021 - Types M and L copper pipes serve as water supply lines in homes, but type L pipes are thicker and have a higher pressure rating than type M copper pipes.