Not all copper tube behaves the same way once it reaches a job site. A large part of that comes down to temper — the metallurgical condition of the tube after drawing and heat treatment — which determines how easily it bends, how strong it is, and how it should be joined.
What Temper Actually Means
During manufacturing, copper tube is drawn through dies to reach its final size, a process that work-hardens the metal. Depending on whether the tube is subsequently annealed (heat treated to soften it) and to what degree, it ends up in one of several standard temper categories.
Soft (Annealed) Temper
Soft temper tube has been fully annealed, making it flexible enough to bend by hand or with simple tools without cracking. It is typically supplied in coils and is common in refrigeration line sets and applications requiring frequent bending during installation.
Half-Hard Temper
Half-hard tube has had only partial annealing, giving it a balance between flexibility and rigidity. It holds its shape better than soft tube but can still be worked with appropriate bending equipment.
Hard (Drawn) Temper
Hard temper tube is supplied in straight lengths with no annealing after the final draw. It offers the highest strength and rigidity of the three, making it suitable for long straight runs, plumbing risers, and applications where structural stiffness matters.
Choosing the Right Temper
- Frequent bends or coiled installation: soft temper
- Moderate forming with some rigidity required: half-hard temper
- Long straight runs, structural applications: hard temper
Frequently Asked Questions
Can hard temper tube be annealed on site?
Localised annealing with a torch is possible before a bend, but it changes the tube’s properties at that point and should be done carefully and only where the application allows it.
Does temper affect pressure rating?
Yes — annealed (soft) tube generally has a lower pressure rating than hard-drawn tube of the same dimensions, which should be factored into system design.
Jaydeep Tubes supplies copper and copper alloy tubes in soft, half-hard, and hard tempers to suit refrigeration, HVAC, and industrial piping requirements.