North American operator manual · V5
EGO ST1520 / ST1520S string trimmer line size
The EGO ST1520 / ST1520S manual V5 specifies nylon line with a diameter no greater than 0.095 inch (2.4 mm) for this tool. This is a maximum, not a recommendation to select the thickest line.
When the trimmer stops while cutting
The manual troubleshooting table lists heavy cutting line among possible causes, alongside missing guard, grass bound around the shaft/head, overload, temperature, battery contact, and depleted battery. It advises using recommended nylon line no greater than 0.095 inch (2.4 mm), fitting the guard, stopping and removing the battery before clearing grass, and allowing hot equipment to cool. Check the full troubleshooting section before assuming that line diameter is the problem.
Head and version check
The manual covers ST1520 and ST1520S and identifies the POWERLOAD feed system. Verify the tool label, fitted head and manual version. A replacement head may have its own compatibility instructions. Source checked October 19, 2026; manual is marked V5. If a newer manual for your serial range differs, use that manual.
Open EGO ST1520 / ST1520S operator manual V5 ↗
Source: official EGO North American operator manual V5. Safety steps in the full manual take precedence.