ASTM B88 Copper Tubes – Types K, L, M

GNEE supplies ASTM B88 seamless copper water tubes suitable for general plumbing and similar applications for the conveyance of fluids. These tubes are available in nominal sizes from 1/2″ through 12″ and are classified into three types according to wall thickness:

Key Material: ASTM B88 seamless copper tubes can be made from commercially pure copper grades UNS C10200, C12000, or C12200. They are commonly used with solder, flared, or compression-type fittings depending on end connection types.

Note: All grades are commercially pure copper with phosphorus added in C12000 and C12200 for deoxidation purposes.

ASTM B88 copper tubes are manufactured by the seamless process involving hot-working, cold-working, and annealing to produce a uniform wrought structure. They are generally furnished in three tempers:

Selection Guide: O60 (soft anneal) offers highest ductility for bending; H58 (drawn) offers highest strength for pressure applications.

Outside Diameter (OD) Tolerances

ASTM B88 Type K Copper Tubes (Thickest – Green Marking)

Application: Type K is the thickest type, mainly used in underground installations where the tube needs to withstand higher pressure or resist potential external damage.

ASTM B88 Type L Copper Tubes (Intermediate – Blue Marking)

Application: Type L has intermediate thickness (thinner than Type K, thicker than Type M), commonly used for general plumbing and heating systems in both residential and commercial buildings.

ASTM B88 Type M Copper Tubes (Thinnest – Red Marking)

Application: Type M is the thinnest type, used in low-pressure applications such as residential water supply and distribution where local codes permit.

GNEE ensures all ASTM B88 copper tubes undergo the following tests and inspections:

Q1: What are the color codes for ASTM B88 Type K, Type L, and Type M copper tubes?
A: ASTM B88 Type K is marked with green color code, Type L with blue, and Type M with red. This color coding helps installers quickly identify the tube type on job sites.

Q2: What is the difference in wall thickness between ASTM B88 Type K, Type L, and Type M for 1″ nominal size?
A: For ASTM B88 1″ tubes: Type K has 0.065″ wall thickness, Type L has 0.050″ wall thickness, and Type M has 0.035″ wall thickness. Type K is the thickest and strongest.

Q3: What copper grades are used for ASTM B88 seamless copper tubes?
A: ASTM B88 tubes are made from commercially pure copper grades UNS C10200 (≥99.95% Cu), UNS C12000 (≥99.90% Cu with 0.004-0.012% P), or UNS C12200 (≥99.90% Cu with 0.015-0.040% P).

Q4: What are the three tempers available for ASTM B88 copper tubes?
A: ASTM B88 tubes are available in O60 (soft anneal) – highest ductility, O50 (light anneal) – medium ductility, and H58 (drawn) – highest strength for pressure applications.

Q5: Can ASTM B88 Type M copper tube be used for residential water supply?
A: ASTM B88 Type M can be used for residential water supply only where local plumbing codes permit. Many jurisdictions require Type L or K for certain applications. GNEE recommends checking local codes before specifying Type M.

Q6: What is the minimum tensile strength for ASTM B88 drawn temper (H58) copper tube?
A: ASTM B88 H58 (drawn) temper has a minimum tensile strength of 36 ksi, which is higher than the 30 ksi minimum for annealed tempers (O60 and O50).

Q7: What is the difference between ASTM B88 and ASTM B280 copper tubes?
A: ASTM B88 covers general plumbing water tubes (Types K, L, M), while ASTM B280 covers air conditioning and refrigeration (ACR) tubes which are cleaned and dehydrated for sealed systems.

Q8: What tests are required for ASTM B88 copper tube certification?
A: ASTM B88 tubes require visual inspection, dimensional examination, chemical analysis, tensile test, hardness test, expansion test, flattening test, eddy current test, and grain size examination. GNEE provides EN10204 3.1 certificates.

Q9: Why is ASTM B88 Type K the thickest type of copper water tube?
A: ASTM B88 Type K has the thickest wall to withstand higher pressure and resist external damage in underground or buried installations. It is also used for high-pressure industrial plumbing.

Q10: What fitting types are compatible with ASTM B88 copper tubes?
A: ASTM B88 tubes are commonly used with solder fittings, flared fittings, or compression-type fittings, depending on the end connection type and application requirements.

Q11: What is the phosphorus content in ASTM B88 UNS C12200 copper tube?
A: ASTM B88 UNS C12200 contains 0.015-0.040% phosphorus, which acts as a deoxidant to improve weldability and corrosion resistance. This grade is often called "phosphorus-deoxidized copper."

We provide professional, export-grade packaging for all copper products including tubes, plates, rods, wires, and strips. Tubes are protected with plastic end caps, PE foam, and woven bags or wooden spools. Plates and sheets are packed with moisture-proof paper and steel strapping inside wooden crates. Rods and bars are wrapped with anti-rust film and placed in fumigation-free wooden cases. Wires are wound on spools or coils, then stretch-wrapped on export pallets. Strips are separated by anti-rust paper and packed in cartons or wooden boxes. All packaging methods are designed to prevent oxidation, scratching, and moisture damage during sea or air freight, with custom labeling and bundling options available.

Our factory is equipped with advanced manufacturing lines for copper tubes, plates, rods, wires, and strips. Key equipment includes horizontal continuous casting furnaces, reverse extrusion presses, cold pilger mills, continuous drawing and rolling lines, in-line annealing furnaces, and precision straightening & cutting machines. For quality control, we operate spectrometers, universal testing machines, eddy current and ultrasonic flaw detectors, and hardness testers. This integrated setup ensures high production efficiency, dimensional accuracy, and consistent mechanical properties across all copper alloy products.

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