ASTM B88 copper tubes are 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: Type K, Type L, and Type M. They are marked with different color codes for easy identification:
| Tube Type | Color Code |
|---|---|
| Type K | Green |
| Type L | Blue |
| Type M | Red |
ASTM B88 seamless copper tubes can be made from commercially pure copper grades UNS C10200, C12000, or C12200. GNEE primarily supplies C12200 grade. These tubes are commonly used with solder, flared, or compression-type fittings depending on end connection types.
Chemical Composition Requirements
| Grade | Copper Content | Phosphorus Content |
|---|---|---|
| UNS C10200 | ≥ 99.95% | Not applicable |
| UNS C12000 | ≥ 99.90% | 0.004% – 0.012% |
| UNS C12200 | ≥ 99.90% | 0.015% – 0.040% |
Tempers & Mechanical Properties
ASTM B88 copper tubes are manufactured by the seamless process involving hot-working, cold-working, and annealing to produce a uniform wrought structure. Tubes may be furnished in coiled or straight length.
| Temper Designation | Name | Product Form | Rockwell Hardness | Tensile Strength | Average Grain Size |
|---|---|---|---|---|---|
| O60 | Soft anneal | Straight lengths or coils | ≤ 50 (Scale F) | ≥ 30 ksi | ≥ 0.040 mm |
| O50 | Light anneal | Straight lengths or coils | ≤ 55 (Scale F) | ≥ 30 ksi | ≤ 0.040 mm |
| H58 | Drawn | Drawn | ≥ 30 (Scale 30T) | ≥ 36 ksi | N/A |
Tests & Inspection
| Visual inspection |
| Dimensional examination |
| Chemical analysis |
| Tensile test |
| Hardness test |
| Expansion test |
| Flattening test |
| Microscopical examination for hydrogen embrittlement |
| Eddy current test |
| Grain size examination |
Sizes, Outside Diameter & Tolerances
| Nominal Size (inch) | Actual OD (inch) | OD Tolerance – Annealed (inch) | OD Tolerance – Drawn (inch) |
|---|---|---|---|
| 1/4" | 0.375 | 0.002 | 0.001 |
| 3/8" | 0.500 | 0.0025 | 0.001 |
| 1/2" | 0.625 | 0.0025 | 0.001 |
| 5/8" | 0.750 | 0.0025 | 0.001 |
| 3/4" | 0.875 | 0.003 | 0.001 |
| 1" | 1.125 | 0.0035 | 0.0015 |
| 1-1/4" | 1.375 | 0.004 | 0.0015 |
| 1-1/2" | 1.625 | 0.0045 | 0.002 |
| 2" | 2.125 | 0.005 | 0.002 |
| 2-1/2" | 2.625 | 0.005 | 0.002 |
| 3" | 3.125 | 0.005 | 0.002 |
| 3-1/2" | 3.625 | 0.005 | 0.002 |
| 4" | 4.125 | 0.005 | 0.002 |
| 5" | 5.125 | 0.005 | 0.002 |
| 6" | 6.125 | 0.005 | 0.002 |
| 8" | 8.125 | 0.006 | +0.002 / -0.004 |
| 10" | 10.125 | 0.008 | +0.002 / -0.006 |
| 12" | 12.125 | 0.008 | +0.002 / -0.006 |
Type K Copper Tube – Wall Thickness, Tolerance & Weight
Type K is the thickest of the three types. Mainly used in underground installations where the tube needs to withstand higher pressure or resist potential external damage.
| Nominal Size (inch) | Wall Thickness (inch) | Tolerance (inch) | Weight (lb/ft) |
|---|---|---|---|
| 1/4" | 0.035 | 0.0035 | 0.145 |
| 3/8" | 0.049 | 0.005 | 0.269 |
| 1/2" | 0.049 | 0.005 | 0.344 |
| 5/8" | 0.049 | 0.005 | 0.418 |
| 3/4" | 0.065 | 0.006 | 0.641 |
| 1" | 0.065 | 0.006 | 0.839 |
| 1-1/4" | 0.065 | 0.006 | 1.04 |
| 1-1/2" | 0.072 | 0.007 | 1.36 |
| 2" | 0.083 | 0.008 | 2.06 |
| 2-1/2" | 0.095 | 0.010 | 2.93 |
| 3" | 0.109 | 0.011 | 4.00 |
| 3-1/2" | 0.120 | 0.012 | 5.12 |
| 4" | 0.134 | 0.013 | 6.51 |
| 5" | 0.160 | 0.016 | 9.67 |
| 6" | 0.192 | 0.019 | 13.9 |
| 8" | 0.271 | 0.027 | 25.9 |
| 10" | 0.338 | 0.034 | 40.3 |
| 12" | 0.405 | 0.040 | 57.8 |
Type L Copper Tube – Wall Thickness, Tolerance & Weight
Type L has intermediate thickness, thinner than Type K but thicker than Type M. Commonly used for general plumbing and heating systems, including both residential and commercial buildings.
| Nominal Size (inch) | Wall Thickness (inch) | Tolerance (inch) | Weight (lb/ft) |
|---|---|---|---|
| 1/4" | 0.030 | 0.003 | 0.126 |
| 3/8" | 0.035 | 0.004 | 0.198 |
| 1/2" | 0.040 | 0.004 | 0.285 |
| 5/8" | 0.042 | 0.004 | 0.362 |
| 3/4" | 0.045 | 0.004 | 0.455 |
| 1" | 0.050 | 0.005 | 0.655 |
| 1-1/4" | 0.055 | 0.006 | 0.884 |
| 1-1/2" | 0.060 | 0.006 | 1.14 |
| 2" | 0.070 | 0.007 | 1.75 |
| 2-1/2" | 0.080 | 0.008 | 2.48 |
| 3" | 0.090 | 0.009 | 3.33 |
| 3-1/2" | 0.100 | 0.010 | 4.29 |
| 4" | 0.110 | 0.011 | 5.38 |
| 5" | 0.125 | 0.012 | 7.61 |
| 6" | 0.140 | 0.014 | 10.2 |
| 8" | 0.200 | 0.020 | 19.3 |
| 10" | 0.250 | 0.025 | 30.1 |
| 12" | 0.280 | 0.028 | 40.4 |
Type M Copper Tube – Wall Thickness, Tolerance & Weight
Type M is the thinnest of the three types. Used in low-pressure applications such as residential water supply and distribution where local codes permit.
| Nominal Size (inch) | Wall Thickness (inch) | Tolerance (inch) | Weight (lb/ft) |
|---|---|---|---|
| 1/4" | Not available | Not available | Not available |
| 3/8" | 0.025 | 0.002 | 0.145 |
| 1/2" | 0.028 | 0.003 | 0.204 |
| 5/8" | Not available | Not available | Not available |
| 3/4" | 0.032 | 0.003 | 0.328 |
| 1" | 0.035 | 0.004 | 0.465 |
| 1-1/4" | 0.042 | 0.004 | 0.682 |
| 1-1/2" | 0.049 | 0.005 | 0.940 |
| 2" | 0.058 | 0.006 | 1.46 |
| 2-1/2" | 0.065 | 0.006 | 2.03 |
| 3" | 0.072 | 0.007 | 2.68 |
| 3-1/2" | 0.083 | 0.008 | 3.58 |
| 4" | 0.095 | 0.010 | 4.66 |
| 5" | 0.109 | 0.011 | 6.66 |
| 6" | 0.122 | 0.012 | 8.92 |
| 8" | 0.170 | 0.017 | 16.5 |
| 10" | 0.212 | 0.021 | 25.6 |
| 12" | 0.254 | 0.025 | 36.7 |
FAQ
Q1: What is the difference between ASTM B88 Type K and Type L copper tube?
A: Type K copper tube has a thicker wall than Type L. For 1/2" tube, Type K wall thickness is 0.049" while Type L is 0.040". Type K is used for underground water mains and high-pressure systems because it resists external damage better. Type L is the standard for interior residential and commercial plumbing. Type K costs about 20-30% more than Type L for the same diameter.
Q2: What is the difference between ASTM B88 Type L and Type M copper tube?
A: Type L copper tube has a thicker wall than Type M. For 1/2" tube, Type L wall is 0.040" while Type M wall is only 0.028". Type L is rated for higher pressure and is approved for both hot and cold water in all plumbing codes. Type M is thinner and only permitted for low-pressure residential applications where local codes allow. Many jurisdictions do not permit Type M for hot water lines.
Q3: What are the color codes for ASTM B88 Type K, L, and M copper tube?
A: Type K copper tube is marked with green color code. Type L copper tube is marked with blue color code. Type M copper tube is marked with red color code. These color markings are printed along the length of the tube for easy identification at job sites. Contractors can quickly identify tube type by looking at the stripe color without measuring wall thickness.
Q4: Can ASTM B88 Type M copper tube be used for hot water lines?
A: It depends on local plumbing codes. Some codes permit Type M copper tube for residential hot water lines because working pressures are low (40-80 psi). However, many jurisdictions and experienced plumbers recommend Type L for hot water because Type M's thinner wall is more susceptible to pitting corrosion and erosion over time. For commercial buildings or high-temperature systems (above 140°F), Type L is strongly recommended.
Q5: What is the difference between C10200, C12000, and C12200 for ASTM B88 copper tube?
A: C10200 is oxygen-free copper (99.95% Cu), used for specialized applications. C12000 has low phosphorus (0.004-0.012%), offering some deoxidation but limited weldability. C12200 has higher phosphorus (0.015-0.040%), providing full deoxidation and excellent brazing/welding properties. For plumbing systems where brazing is required, C12200 is the standard choice. C12000 is less common for water tube applications.
Q6: What does temper O60 mean for ASTM B88 copper tube?
A: O60 is a soft annealed temper for ASTM B88 copper tube. The tube is heated to at least 600°F and cooled slowly, which removes internal stresses and makes the tube highly ductile. O60 tube can be easily bent and flared by hand using simple tools. It is available in both straight lengths and coils. O60 is the most common temper for plumbing copper tube because field bending is often required during installation.
Q7: What does temper H58 mean for ASTM B88 copper tube?
A: H58 is a hard drawn temper for ASTM B88 copper tube. The tube is cold worked (drawn) and not annealed, so it maintains high strength (minimum 36 ksi tensile strength vs. 30 ksi for annealed). H58 tube is straight and rigid, used for long straight runs where bending is not required. H58 cannot be bent without cracking unless it is annealed first. It is typically used for main supply lines in commercial buildings.
Q8: What is the burst pressure of ASTM B88 Type L 1/2" copper tube?
A: For 1/2" Type L copper tube (0.040" wall thickness), the burst pressure at room temperature is approximately 2,800-3,000 psi. The safe working pressure is derated to 1/4 of burst pressure, or about 700-750 psi. For hot water at 180°F, reduce working pressure by 15-20% because copper strength decreases at elevated temperatures. Typical residential water pressure is 40-80 psi, well within safe limits.
Q9: Why does ASTM B88 allow C10200, C12000, and C12200 for copper tube?
A: ASTM B88 allows multiple copper grades because different applications have different requirements. C10200 (oxygen-free) is for specialized high-conductivity or high-vacuum applications. C12000 (low phosphorus) is an older grade still found in some inventories. C12200 (standard phosphorus-deoxidized) is the most common because it resists hydrogen embrittlement during brazing. For most plumbing jobs, C12200 is the recommended and most available grade.
Q10: What is the weight of ASTM B88 Type L 1" copper tube per foot?
A: ASTM B88 Type L 1" copper tube has a wall thickness of 0.050" and weighs approximately 0.655 pounds per foot. For a standard 20-foot length, the tube weighs about 13.1 pounds. This weight is useful for calculating shipping costs and determining support spacing. For comparison, Type K 1" tube weighs 0.839 lb/ft (heavier), and Type M 1" tube weighs 0.465 lb/ft (lighter).
How Do We Package Copper Heat Exchanger Tubes for Global Delivery?
Poor packaging destroys even the best copper heat exchanger tube. As a professional copper heat exchanger tube factory serving copper heat exchanger tube USA, Europe, UAE, Saudi Arabia, and India, we follow military-grade export packaging standards to ensure zero damage during sea or air freight.
Our Standard Packaging Process:
| Packaging Stage | Material / Method | Purpose |
|---|---|---|
| Individual Tube Protection | Anti-rust VCI paper + plastic end caps | Prevents moisture, dust, and scratches on copper tube heat exchanger inner surfaces. |
| Bundling | Nylon straps + wooden spacers | Keeps copper heat exchanger tube OD 19mm, 1 inch, or 5/8 inch sizes organized and vibration-free. |
| Moisture Barrier | Thick PE film wrap (heat-shrunk) | Blocks humidity during long sea voyages to copper heat exchanger tube Germany or Saudi Arabia. |
| Outer Packing | Export-grade plywood cases or steel-banded wooden crates | Withstands stacking and rough handling. Each crate labeled with PO number, alloy (e.g., SB111 C70600), and quantity. |
| Documentation | Packing list + Mill Test Certificate (MTC) attached outside | Customs clearance support for copper heat exchanger tube stockist and distributor partners. |
For U-Bundle Orders: U tube heat exchanger and U tube bundle heat exchanger are placed in dedicated steel jigs inside the crate to prevent bending radius distortion.
Our Factory & Equipment
| Equipment Type | Specification / Capability | Quality Impact |
|---|---|---|
| Horizontal Continuous Casting Line | 10-ton capacity | Produces homogeneous copper alloy tube for heat exchanger billets with zero porosity. |
| Three-Roll Piercing Mill | Up to 60mm OD | Precision wall thickness control for heat exchanger tube wall thickness as low as 0.5mm. |
| Cold Drawing Bench | 5 draws in sequence | Achieves tight tolerances on copper heat exchanger tube length and heat exchanger pipe diameter. |
| Straightening & Cutting Line | CNC servo-controlled | Burr-free cutting for copper heat exchanger tube 3/4 inch and 1 inch to exact project lengths. |
| U-Bending Machine | CNC mandrel type | Produces u tube condenser and U tube bundle heat exchanger without kinking or ovality. |
| Eddy Current Tester | NDT (Non-Destructive Testing) | 100% inspection of C70600 tube and C71500 tube for pinholes or cracks per ASTM B111 pdf standards. |
| Hydrostatic Tester | Up to 200 bar | Validates heat exchanger tube expansion and tube rolling integrity. |
| Spectrometer | Optical emission (OES) | Confirms chemical composition of ASME SB111, EN 12451, and JIS H3300 grades on every batch. |
Our Certifications & Compliance:
ASTM B111 pdf and ASME SB111 pdf full traceability.
ISO 9001:2015 quality management system.
Third-party inspection accepted: SGS, BV, Lloyds, or TUV.
Copper heat exchanger tube life expectancy testing reports available upon request.
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