Why Copper Tubing for Lubrication Lines
Most lubrication circuits are plumbed with nylon or polyamide tube: polymer is light, flexible, and quick to route. Copper keeps a narrower, harder job. This 6mm OD x 1mm wall tube in C12200 phosphorus deoxidized copper is built for the sections of a lubrication system where polymer struggles: runs passing close to engines, compressors, or ovens where heat softens nylon, and short exposed runs where a hard wall resists abrasion. For ordinary ambient circuits, a nylon line is usually the simpler choice.
The same tube suits small pneumatic control and instrument lines, so one stock covers several duties around a central lubrication system. The tube is seamless and cold-drawn, with a clean, oxide-free finish that accepts soldered or compression joints.
Specifications and Available Lengths
| Item | Specification |
|---|---|
| Outer Diameter | 6mm |
| Inner Diameter | 4mm |
| Wall Thickness | 1mm |
| Material | C12200 phosphorus deoxidized copper |
| Construction | Seamless cold-drawn |
| Working Pressure | 4.8 MPa (696 psi) @20°C |
| Working Temperature | -200°C to 400°C |
| Tensile Strength | at least 220 MPa |
| Heat Conductivity | 401 W/mK |
| Weight | 140 g/m |
| Minimum Bend Radius (annealed) | 18mm (3x OD) |
| Available Lengths | 300mm, 1m, 3m |
The 4.8 MPa (696 psi) @20°C rating is a room-temperature figure; like any metal tube, the allowable pressure falls as temperature rises, so confirm the rating at your actual operating temperature before laying out a hot-service run. The tube is supplied in 300mm, 1m, and 3m lengths. Send your line list and joint count through our quote request form for tube and fittings together.
Where This Tube Fits in a Lubrication System
We position this tube for a focused set of duties:
- Centralized lubrication lines – primary and secondary feeds in grease and oil systems, where a rigid run holds its shape and protects the flow path.
- Pneumatic control circuits – instrument-quality air lines on automation equipment.
- Small hydraulic and instrument tubing – low-pressure sensing and actuation lines.
- Hot-zone routing – the short sections near engines, bearings, or ovens where nylon would soften and copper keeps the line intact.
For a wider map of tube and hose materials, see our lubrication tubing and hose selection guide and the high-pressure hose category.
Installation Notes
Cut the tube with a mini tube cutter for a square end, deburr inside and out, and braze joints with nitrogen flowing through the tube to limit internal oxidation; without nitrogen, keep joints few and flush the line after joining. Support runs at about 1.2m intervals, and where copper meets steel or aluminum hardware, fit a dielectric union or isolate the metals to slow galvanic corrosion.
Be realistic about the trade-offs. Bending must be done in the annealed state with a tube bender; the minimum bend radius is 18mm, or 3x the OD. Rigid lines must be pre-bent to the machine, which adds fabrication time versus clipping in nylon. At 140 g/m the tube weighs more than a polymer line of the same size, so long vertical runs need proper support. Plan the route and order spare length for bends and rework.
Frequently Asked Questions
When should I choose copper tubing instead of nylon pipe for a lubrication line?
Choose copper when the line crosses a hot zone, rubs against moving parts, or must hold a fixed shape. Choose 6mm nylon pipe for ambient-temperature runs, vibrating sections, and long flexible pulls.
What working pressure and temperature does this tube allow?
4.8 MPa (696 psi) @20°C, and -200°C to 400°C on temperature. Treat the pressure as a room-temperature value; confirm with us once the line runs hot.
Can I bend this tube by hand?
Only soft-annealed tube bends readily, and even then use a tube bender. The minimum bend radius is 18mm, or 3x the OD. Bending hard-drawn tube risks kinking; anneal the section first or use fittings.
What fittings work with this tubing?
Soldered joints and compression fittings both work; compression suits field assembly and repair. Matching brass compression sleeve fittings cover the common lubrication line connections.
How do I cut and join copper lubrication lines cleanly?
Use a mini tube cutter for a square end, deburr thoroughly, and braze with nitrogen flowing through the tube to limit internal oxide. Flush the completed line before hooking it to a pump.
Is copper tubing heavier than nylon, and does it matter?
Yes. At 140 g/m this tube weighs noticeably more than a polymer line of the same size, so support runs at 1.2m intervals with clips or brackets.
Can I connect copper directly to steel or aluminum parts?
Direct contact in a damp environment sets up galvanic corrosion. Use a dielectric fitting or isolate the metals with a non-metallic sleeve or washer at the joint.
What lengths are available, and how much should I order?
300mm, 1m, and 3m. Measure each run, add length for bends and fittings, then add spare for rework; a rigid line cannot be stretched the way a hose can.
Where is copper tubing the wrong choice?
Skip it for long flexible runs, on vibrating assemblies without isolation, and for ordinary ambient circuits where nylon installs faster and cheaper. Points beyond the stated pressure and temperature ratings also rule it out.
How do I order, and who supports the product?
Send your line list, lengths, and joint count through the quote request page or email inquiry@isohitech.com. IsoHiTech Lubrication Systems was founded in 2023, engineering since 2006, and we can confirm temperature derating, joint methods, and fitting selection before you order.
