We still can produce coil with 12 fpi.Typically for the coil. We can produce with 12 fpi.But we want to increase the bending coil, density of the fin, as 14 of the fpi to the broken coil during lieng bending.
We can still produce coils with 12 fpi usually for general Coyle. We can produce about 12 fpi coil bending but we want to increase the density of fish as much as 14 fpi to avoid fracture of the coil during bending.