Extension Springs AQS manufactures extension springs from a wide range of wire types and sizes. We can coil springs from wire as small as 0.004" (0.1mm) diameter to as large as 0.200" (5.0mm) diameter. We can make a variety of different types of extension springs with crossover loops, machine hooks, extended hooks, and drawbar style. High or low volumes, we can be competitive on your extension springs.