Introduction
This article explains the application scenarios of T2 and T3 copper materials. T2 and T3 are Chinese designations for commercial copper defined in GB/T 5231, where the number indicates the purity level. T2 is the standard grade for electrical and general industrial use, and T3 is a lower-cost grade with slightly higher impurity limits.
Grade Definitions
T2 copper contains at least 99.90 percent copper, while T3 contains at least 99.70 percent with correspondingly higher limits on oxygen and other impurities. The purity difference affects conductivity and ductility, so T2 is preferred for electrical and forming applications and T3 is used where cost dominates and the requirements are less demanding.
Products and Forms
Both grades are supplied as sheet, strip, plate, rod, bar, wire, tube and forgings. The product standards define the dimensional tolerances and mechanical properties for each form, with drawn and annealed tempers available.
| Grade | Cu % Min | Typical Use |
|---|---|---|
| T2 | 99.90 | Bus bars, tube, terminals |
| T3 | 99.70 | Roofing, flashing, gaskets |
Applications
T2 is used for bus bars, terminals, tube for plumbing and refrigeration, sheet for stampings and general electrical hardware. T3 is used for roofing, flashing, gaskets, and components where the slightly lower conductivity and ductility are acceptable in exchange for lower material cost.
Selection and Verification
Match the grade to the conductivity and forming requirements, and verify the copper content and mechanical properties on the certificate against GB/T 5231 and the relevant product standard.
