Minneapolis pattern curb boxes have female threads machined into the bottom of the base casting that screw onto the male threads on top of all Minneapolis pattern curb stops. Threading the curb stop into the curb box gives a unified valve/box assembly. This arrangement ensures alignment between the two. Shut-off rod information noted above is also true when used with Minneapolis pattern curb boxes with 1 in upper section. The charts below identify size of threads in base casting A.Y. McDonald curb boxes and curb stops.