The Physics: The load capacity of a gooseneck arm depends on the torque balance. Torque = Weight × Length. This means if you double the length, you need to double the diameter to maintain the same load capacity.
The Rule: For a 300mm standard length, use this quick reference: 8mm for under 300g, 10mm for 300-600g, 12mm for 600g-1.2kg, 15mm for 1.2kg-2.5kg.
Pro Tip: If your lamp head exceeds 1kg and your gooseneck length exceeds 500mm, we recommend using 14mm or 16mm diameter. For CNC environments with vibration, consider upgrading one size larger for safety margin.
