Published: 2026-08-26
The biggest pitfall in cable industry purchasing is the falsely labeled cross-section — labeled as 4 square millimeters, but the actual copper wire is a circle smaller. The direct consequence of an insufficient cross-section is reduced current-carrying capacity and increased heating, which at best causes tripping and at worst can start a fire.
Four methods of on-site inspection:
First, measure the outer diameter. The more copper wires there are, the larger the cross-section; the outer diameter does not lie. Use a caliper to measure the sheath's outer diameter, and the deviation should be within the allowable range according to the national standard table (generally around ±0.5mm).
Second, weigh it. For cables of the same length, copper accounts for more than 70% of the weight. If you weigh 1 meter of cable on an electronic scale and it is noticeably lighter, you need to be cautious.
Third, count the copper wires. Strip the sheath and count the number of copper wires, measure the diameter of a single wire, and calculate the total cross-sectional area: Cross-sectional area = single wire diameter² × 0.785 × number of wires.
Fourth, look at the copper color. High-quality oxygen-free copper has a bright copper color, while recycled copper appears dark and brittle, breaking after a few bends.
Special attention: Some manufacturers use 'conductor resistance meets standards' as an excuse, but cables with insufficient cross-section may also pass the resistance test (because of high copper purity), so cross-section inspection should not rely solely on resistance; it should comprehensively consider outer diameter, weight, and copper strands.
All cables produced by Shanghai Suoqi Cable meet the national standard in full quantity. Third-party inspection reports can be provided, and when purchasing special cables, sectional area and resistance test data can be requested for comparison and acceptance.
About Shanghai Suoqi
Shanghai Suoqi Electric Wire & Cable Co., Ltd. is a specialized cable enterprise focusing on the research and development, design, production, and sales of special flexible cables. The company's products cover a series including reel cables, flat cables, drag chain cables, encoder cables, polyurethane cables, seawater-resistant cables, seawater-resistant network cables, and high-altitude vehicle cables, which are widely used in ports machinery, mining, industrial automation, marine engineering, and other fields. For more product information or inquiries, please call 13311756197 (same number on WeChat).