Tilt window pivot

Thanks for your posting! This window hardware reminds me of the 15-253 Inverted Universal Triple Support. This is compatible with the 1/2" wide Series 160 Coil Balance. 

To determine the coils needed to complete your assembly, you'll need to check for any stamps/markings on the coil springs. If there aren't any, you'll need to obtain the exact weight of the sash and divide that by the total number of coils in the window (in your case, 6).

DImensions for 15-253