Appearance : surface smooth and bright  ,colour uniform , and without the defect of detinning ,black spot , crack , yellowing and scrap tin etc.

Diameter :  allowable deviation ±0.000mm.

 Elongation:≥20%(according to the clients' needs )

Reverse bending :≥5

Aging Test :No yellowing and black when baking one hour at the temperature of 200±5°C..

Continuity:under the test of the tinned copper wire is dipped into  hydrochloric acidand sodium polysulfide for three weeks ,there is no exposed copper and black spots.

Binding force:under the test of winding six laps tinned copper wire is dipped into the sodium polysulfide,there is no crack and black to appear. 

Tinned copper wire lasts up to 10 times longer than non-tinned wire. It also resists water corrosion and provides enhanced conductivity.

These are standard circular bare copper conductors mainly used for :

a) Overhead transmission system   b) Overhead traction system

c) Transformer earthing (occasionally)