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Views: 0 Author: Site Editor Publish Time: 2026-07-28 Origin: Site
Choosing the right copper pipe size is one of the first steps in HVAC, refrigeration and plumbing projects. A small mistake in outside diameter, wall thickness, standard or temper can cause fitting mismatch, leakage risk, installation delay or unnecessary purchasing cost.
As a copper tube manufacturer in China, Fengdie Metal supplies seamless copper pipe, pure copper tube, ACR copper tube and copper coils in both inch and metric sizes. This copper pipe size chart helps buyers compare common HVAC copper pipe sizes, plumbing copper tube sizes and international standards before sending an inquiry.
For HVAC and refrigeration, copper tube is usually ordered by outside diameter, especially under ASTM B280. The table below shows common inch copper tube sizes and their metric equivalents.
| Inch Size | Metric OD | Common Use |
| 3/16" | 4.76 mm | Small refrigeration lines, capillary-related applications |
| 1/4" | 6.35 mm | Split AC, refrigeration service, small liquid lines |
| 5/16" | 7.94 mm | Refrigeration and appliance tubing |
| 3/8" | 9.52 mm | HVAC liquid lines, refrigeration systems |
| 1/2" | 12.70 mm | Air conditioning, heat pumps, plumbing connections |
| 5/8" | 15.88 mm | HVAC suction lines, medium-capacity systems |
| 3/4" | 19.05 mm | Larger AC units, refrigeration and plumbing |
| 7/8" | 22.23 mm | Commercial HVAC and refrigeration |
| 1" | 25.40 mm | Industrial cooling and plumbing |
| 1-1/8" | 28.58 mm | Commercial refrigeration and larger line sets |
| 1-3/8" | 34.93 mm | Industrial HVAC and cooling systems |
| 1-5/8" | 41.28 mm | Large refrigeration systems |
| 2-1/8" | 53.98 mm | Commercial and industrial refrigeration |
Metric copper tube sizes are commonly used in Europe, the UK, Japan and many engineering projects. EN 12735 is often used for air conditioning and refrigeration copper tubes, while EN 1057 is commonly used for plumbing and water applications.
| Metric OD | Common Application |
| 6 mm | Small refrigeration lines, instrument tubing |
| 8 mm | HVAC, refrigeration, light plumbing |
| 10 mm | Metric refrigeration systems, heat pumps |
| 12 mm | HVAC and plumbing installations |
| 15 mm | Plumbing, water supply, heating systems |
| 18 mm | Plumbing, heating and light industrial systems |
| 22 mm | Water supply, HVAC and gas-related installations |
| 28 mm | Larger plumbing and heating systems |
| 35 mm | Commercial plumbing and heat exchange |
| 42 mm | Industrial fluid systems |
| 54 mm | Large plumbing, cooling and mechanical systems |
Important note: inch sizes and metric sizes should not be treated as the same. For example, 3/8" copper tube is 9.52 mm OD, not 10 mm. If your fittings are metric, confirm the exact outside diameter before ordering.
For standard comparison, you can also read: ASTM B280 vs EN 12735: ACR Copper Tube Standards Guide.
For plumbing projects, especially in North American markets, copper pipe may be ordered by nominal size rather than exact outside diameter. This is different from ACR copper tube.
| Nominal Plumbing Size | Actual OD | Typical Use |
| 1/4" | 3/8" / 9.52 mm | Small water or service lines |
| 3/8" | 1/2" / 12.70 mm | Light plumbing connections |
| 1/2" | 5/8" / 15.88 mm | Residential water supply |
| 3/4" | 7/8" / 22.23 mm | Main water lines, heating |
| 1" | 1-1/8" / 28.58 mm | Larger plumbing systems |
| 1-1/4" | 1-3/8" / 34.93 mm | Commercial plumbing |
| 1-1/2" | 1-5/8" / 41.28 mm | Commercial water systems |
| 2" | 2-1/8" / 53.98 mm | Large plumbing and mechanical systems |
Type K, Type L and Type M refer mainly to wall thickness. Type K is usually the thickest, Type L is medium, and Type M is thinner. The right type depends on pressure, installation method, local code and project requirements.
| Buyer Information | Example |
| Application | HVAC, refrigeration, plumbing, heat exchanger |
| Standard | ASTM B280, ASTM B88, EN 1057, EN 12735 |
| Copper grade | C12200, C11000, C10200, Cu-DHP |
| Outside diameter | 1/4", 3/8", 1/2", 10 mm, 15 mm, 22 mm |
| Wall thickness | Confirm by drawing or standard |
| Form | Straight length, pancake coil, LWC |
| Temper | Soft annealed, half-hard, hard drawn |
| Surface requirement | Bright annealed, cleaned, capped, nitrogen sealed |
| Certificate | EN 10204 3.1, chemical and mechanical report |
Fengdie Metal manufactures seamless copper tubes and copper pipes for international buyers who need stable quality, flexible MOQ and export-ready documentation. Our copper tube products cover C12200 / TP2 / Cu-DHP, C11000, C10200 and copper alloy grades for HVAC, refrigeration, plumbing, heat exchangers and industrial systems.
As a copper pipe supplier from China, we support:
Inch and metric copper tube sizes
ASTM B280, ASTM B75, ASTM B88, EN 1057 and EN 12735 standards
Straight copper pipe, pancake coil and level wound coil
Cut-to-length and custom wall thickness
Bright annealing, cleaning, capping and export packing
EN 10204 3.1 certificate and test reports
For current copper tube price, MOQ and lead time, contact Fengdie here: Get a Copper Tube Quote
Common HVAC copper pipe sizes include 1/4", 3/8", 1/2", 5/8", 3/4" and 7/8". The final size depends on system capacity, refrigerant type, line length and equipment design.
No. 3/8" copper tube has an outside diameter of 9.52 mm, while 10 mm copper tube is a metric size. They should not be mixed unless the fitting supplier confirms compatibility.
ACR copper tube is used for air conditioning and refrigeration. It usually requires a clean inner surface, capped ends and often nitrogen-sealed packaging. Plumbing copper pipe is used for water, gas or heating systems and may follow standards such as ASTM B88 or EN 1057.
C12200 / TP2 / Cu-DHP is widely used for ACR copper tube because it offers good brazing performance, corrosion resistance and reliable processing for coils and straight lengths.
Yes. Fengdie can supply standard and custom copper tube sizes, including non-standard OD, wall thickness, cut-to-length straight pipes, pancake coils and special packing requirements.
For refrigeration and air conditioning service, capped, cleaned and nitrogen-sealed copper tube is strongly recommended. It helps protect the inner surface from moisture, dust and contamination before installation.
