Copper Tubing

Long lasting copper tube is a favorite choice for plumbing, heating, cooling and other systems. In the United States, it is manufactured to meet the requirements of specifications established by the American Society for Testing and Materials (ASTM).

Tube supplied to these ASTM standards is a minimum of 99.9 percent pure copper. The copper customarily used for tube supplied to these specifications is deoxidized with phosphorus and referred to as c12200 (Copper no. 122) or DHP Copper. Other coppers may also be used.

Type K, L, M, DWV and Medical Gas tube are designated by ASTM standard sizes, with the actual outside diameter always 1/8-inch larger than the standard size designation. Each type represents a series of sizes with different wall thicknesses. Type K tube has thicker walls than Type L tube, and Type L walls are thicker than Type M, for any given diameter. All inside diameters depend on tube size and wall thickness.

Temper describes the strength and hardness of the tube. In the piping trades, drawn temper tube is often referred to as "hard" tube and annealed as "soft" tube. Although drawn tube may also be furnished in a "bending temper", it is not covered by STM B 88. This special temper of intermediate strength and hardness may be specified for applications requiring bending. Tube in the hard temper condition can be joined by soldering or brazing, using capillary fittings or by welding.