National Standard Thickness Error of Cable Trays

The national standard thickness of cable trays varies by material, with steel at 1.2 mm, aluminum at 1.5 mm, and fiberglass at 3.5 mm, and allowable thickness deviations are defined by the T/CECS 31-2017 standard.

Standard Thickness by Material

According to the T/CECS 31-2017 national standard, implemented in 2018, the minimum thickness requirements for cable trays are as follows:

• Steel trays: 1.2 mm for tray widths between 150 mm and 300 mm
• Aluminum alloy trays: minimum 1.5 mm
• Fiberglass trays: minimum 3.5 mm
• Stainless steel trays: typically manufactured using AISI 316L (U.S.) grade stainless steel, with thicknesses following manufacturer specifications and national standards These thicknesses apply to the tray base, cover plates, and connecting plates, while protective layers such as zinc coatings or paint are measured separately .

Thickness Error and Tolerances

While the exact numerical tolerance is not always explicitly listed in public summaries, the T/CECS 31-2017 standard and related national standards generally define thickness error as a permissible deviation from the nominal thickness, typically expressed as a percentage or fixed millimeter range. For example:

• Steel and aluminum trays: manufacturing tolerances are often ±0.1 mm to ±0.2 mm depending on tray width and production method
• Fiberglass trays: tolerances are slightly larger due to pultrusion processes, often ±0.3 mm
• Coatings: zinc or paint layers have separate thickness tolerances, e.g., hot-dip galvanization may vary ±10% of the nominal coating thickness These tolerances ensure that trays maintain structural integrity, load-bearing capacity, and compliance with safety standards.

Additional Considerations

• Material selection affects both thickness and tolerance; stainless steel trays are more corrosion-resistant and may have stricter tolerances for critical installations
• Tray width and type (ladder, ventilated, solid-bottom) influence the required thickness and allowable deviation
• Inspection and quality control: national standards specify sampling methods and classification of unqualified products based on thickness deviations For precise tolerance values, it is recommended to consult the full T/CECS 31-2017 standard or the manufacturer's technical specifications, as these provide the legally binding and tested limits for thickness errors.