304 Stainless Steel Main Tube with Copper Connection Ends
A hybrid tube solution for HVAC evaporators, refrigeration equipment and commercial air-conditioning assemblies where the main tube is changed to stainless steel while copper end sections are retained for connection and downstream fabrication.
Current standard lengths are 2000 mm and 3000 mm. Other lengths, tube sizes and copper-end dimensions can be reviewed according to the project drawing or agreed dimensions.
For selected designs, it can be reviewed—but not as a blind one-for-one material substitution.
One practical route is a 304 stainless steel main tube with copper tube ends. The equipment can keep copper connection sections while the main tube material is changed. Heat transfer, wall thickness, refrigerant, pressure, transition design and finished-equipment approval still need to be checked for the actual application.
For the wider engineering logic, see the Copper Tube Replacement Review and our article on stainless steel replacing copper in heat exchangers.
The tube substrate and connection design are specified separately from the external appearance. Copper plating can be added where a copper-colored finish is preferred, while the substrate remains stainless steel.
The main tube section remains visibly stainless steel. Copper sections are joined at both ends for downstream connection or assembly. Copper-end OD, wall, length and end form should follow the equipment requirement.
Copper plating can be reviewed where a copper-colored external appearance is required. The substrate remains stainless steel and should continue to be identified as stainless steel in the drawing and purchasing specification.
For an evaporator or refrigeration assembly, the stainless-to-copper transition is not only a cosmetic detail. Buyers should define the end geometry and finished assembly condition together with the main stainless tube size.
The actual end profile may differ by customer assembly. Formed, expanded or flared end conditions should be specified by drawing or agreed dimensions. External copper plating is a separate finish option.
304 is the main stainless grade currently used for this product direction. Standard lengths are 2000 mm and 3000 mm. Other OD, wall thickness, length, copper-end dimensions and end geometry can be reviewed by project.
| OD × Wall | Standard Length | Current Construction |
|---|---|---|
| 16 × 1.0 mm | 2000 / 3000 mm | 304 stainless steel body + copper tube ends |
| 19 × 1.0 mm | 2000 / 3000 mm | 304 stainless steel body + copper tube ends |
| 22 × 1.0 mm | 2000 / 3000 mm | 304 stainless steel body + copper tube ends |
| 25 × 1.0 mm | 2000 / 3000 mm | 304 stainless steel body + copper tube ends |
| 28 × 1.0 mm | 2000 / 3000 mm | 304 stainless steel body + copper tube ends |
| 32 × 1.2 mm | 2000 / 3000 mm | 304 stainless steel body + copper tube ends |
| 35 × 1.2 mm | 2000 / 3000 mm | 304 stainless steel body + copper tube ends |
| 38 × 1.2 mm | 2000 / 3000 mm | 304 stainless steel body + copper tube ends |
| 42 × 1.4 mm | 2000 / 3000 mm | 304 stainless steel body + copper tube ends |
| 45 × 1.5 mm | 2000 / 3000 mm | 304 stainless steel body + copper tube ends |
| 48 × 1.5 mm | 2000 / 3000 mm | 304 stainless steel body + copper tube ends |
| 50 × 1.5 mm | 2000 / 3000 mm | 304 stainless steel body + copper tube ends |
The key question is not simply whether stainless steel can replace copper. The finished geometry, copper connection interface, heat-transfer duty and pressure requirement all have to work in the equipment design.
This construction is especially relevant where an OEM wants to reduce the copper content of the main tube while retaining copper ends for downstream connection and assembly.
See also Condenser & Evaporator Tubes, Industrial Refrigeration Tubes and Heat Exchanger Tubes.
Tube OD and wall, 2000 / 3000 mm standard length or custom length, copper-end geometry, forming requirement, refrigerant / working medium, design pressure and leak requirement should be reviewed together. When copper plating is specified, the stainless substrate should remain clearly identified in the purchasing specification.
There is no single pressure rating for this entire product family. The finished assembly should be reviewed against the actual refrigerant, design pressure, test pressure, temperature, tube dimensions, transition geometry and equipment specification.
Provide the equipment or circuit design pressure rather than asking for a generic tube pressure rating.
Specify the required pressure or leak test method and the acceptance criterion for the tube or finished assembly.
Refrigerant type and operating / design temperature affect the pressure envelope and the material / joint review.
This hybrid construction is not a universal direct replacement. For the wider engineering comparison, see Can Stainless Steel Tubes Replace Copper Tubes in Heat Exchangers?
Stainless steel and copper do not have the same thermal properties. Tube wall, heat-transfer area and equipment performance should be reviewed rather than copied one-for-one.
The stainless tube and stainless-to-copper transition are both part of the pressure circuit. Design pressure, test pressure and leak acceptance should be defined by the equipment requirement.
Copper ends can preserve the required connection interface, while end forming, bending, assembly and any external plating should follow the finished product requirement.
If one of the current sizes and 2000 / 3000 mm standard lengths already fits your project, a drawing is not required to start the quotation. For custom dimensions or end geometry, dimensions or a drawing are helpful when available.
Stainless Grade: 304 Stainless Tube OD × WT: Overall Length: 2000 / 3000 mm / Custom Copper End OD × WT: Copper End Length: End Form / Connection: Copper Plating: Yes / No Application: Refrigerant / Working Medium: Operating / Design Temperature: Design Pressure: Test / Leak Requirement: Quantity: Drawing / Standard: Inspection / Documentation: Destination:
Use these pages for broader copper-replacement logic, stainless tube supply and refrigeration / heat-exchanger application review.
Common questions from HVAC, refrigeration and evaporator buyers reviewing stainless steel as an alternative to an all-copper main tube.
It can be reviewed in selected HVAC/R and evaporator designs, but it is not a direct drop-in material change. A practical construction is a 304 stainless steel main tube with copper ends, with heat transfer, wall thickness, refrigerant, pressure, transition design and finished-equipment approval checked for the actual project.
This construction can be reviewed when the main tube is being changed to stainless steel but the equipment still benefits from copper connection sections at the ends.
304 is the main grade currently used for this configuration. Other stainless grades can be reviewed where the customer specification or service condition requires them.
No. Copper plating is an optional external surface finish. The substrate remains stainless steel and should be identified as stainless steel in the technical specification.
The current standard lengths are 2000 mm and 3000 mm. Other lengths, OD, wall thickness, copper-end dimensions and end forms can be reviewed according to the application and quantity.
There is no universal pressure rating for the whole product family. Pressure capability depends on tube size, wall thickness, material, transition geometry, refrigerant, temperature and the finished assembly design. Send the design pressure and test requirement with the RFQ.
If one of the listed sizes and 2000 / 3000 mm standard lengths fits your requirement, send the size, quantity and application. For custom OD, wall, length or copper-end geometry, send the dimensions or a drawing if available.
