: Measured by the thickness of the steel wire itself. A common way to determine this is to measure 20 coils and compare the result to a wire size chart.
To buy the correct replacement, you must identify four primary measurements from your existing, broken spring: buy garage door torsion springs
: Most residential doors use a 2-inch or 1.75-inch inside diameter. This is often stamped on the stationary cone at the end of the spring. : Measured by the thickness of the steel wire itself