Copper water tube is specified by type, which describes wall thickness, not diameter. Type M is the thinnest and is common in residential water distribution; Type L is heavier and is the usual requirement for underground runs and commercial work; Type K is heaviest and is what most codes call for on water services buried between the main and the building.
Hard copper comes in straight 10' and 20' lengths and is soldered or pressed. Soft copper ships in coils, bends by hand or with a tubing bender, and is used where a continuous run without joints matters — underground services, refrigeration lines, and gas connections.
Note that copper tube is sized by nominal diameter, and the actual outside diameter is 1/8" larger: a 1/2" tube measures 5/8" across. Fittings follow the nominal number, so a 1/2" elbow fits 1/2" tube. ACR tubing for refrigeration is the exception — it is labeled by true outside diameter and is cleaned, capped and nitrogen-purged at the factory.
Sizing a run? Our copper pipe and tube dimensions give OD, wall and ID for Type K, L and M per ASTM B88, plus DWV and ACR sizing, temper and joining methods.
We carry Mueller Streamline and other manufacturers in Types K, L and M, hard and soft, plus refrigeration and medical gas tube.
















































