Prime Quality Copper Square Tube Pipe For Air Conditioners Refrigerators Square Copper Tube

Red Copper Square Tube – Process and Quality Assurance

Our red copper square tubes are manufactured from high-purity oxygen-free copper (Cu ≥ 99.95%) or T2 copper cathode using a fully controlled process: continuous upcasting/horizontal continuous casting → multi-pass cold extrusion → intermediate annealing → drawing to final size → finishing and straightening → NDT inspection → cleaning and protective packaging. This ensures dense microstructure, uniform grain size, and consistently excellent electrical and thermal conductivity.

Key process features

● High extrusion ratio (≥ 30:1) in the extrusion stage effectively breaks coarse as-cast grains and achieves full recrystallization;
● Multi-pass drawing combined with two vacuum bright annealing cycles eliminates internal stress and prevents intergranular oxidation, maintaining high cleanliness both on surface and inside the material;
● Dimensional tolerances controlled within ±0.05 mm, wall thickness variation ≤ 3%, straightness ≤ 0.5 mm/m, and superior diagonal Consistency exceeding first-class national standard requirements;
● 100% eddy current testing supplemented by ultrasonic inspection eliminates surface and subsurface cracks, inclusions, orange peel, and other defects.

Quality control system

● Incoming raw material inspected batch-by-batch with direct-reading spectrometer for chemical composition and hydrogen/oxygen content;
● SPC process control implemented at each production stage; critical dimensions measured and recorded 100% online;
● Before shipment, every single tube undergoes electrical conductivity testing (≥ 101% IACS), eddy current flaw detection, pressure tightness test (15 bar × 30 min, zero leakage), full dimensional inspection, and surface quality verification;
● Third-party inspection reports (SGS, BV, AHK, etc.) and complete production traceability records available upon request.

Ideally suited for large-section busbars, heat exchanger tubing, water-cooling plates in new energy systems, industrial conductive connectors, and other applications where dimensional precision, electrical conductivity, gas tightness, and long-term reliability are mission-critical.

We specialize in supplying consistent, fully traceable, high-performance red copper square tubes to leading industry players worldwide.