I'm working on a PCB that has through-hole components on both sides of the board. The "top" side of the board is mounted flush to a Delrin plastic block (the only top-side component is a gas sensor that is fed air samples through hose fittings in the plastic block).
The flush mounting means that I have to add grooves to the plastic block to accommodate the soldered pins of the bottom-side components. Assuming a standard 0.062" thickness FR4 board, how deep do I need to make the grooves in the plastic block? The only thing I could find is this NASA workmanship standard that states 0.5mm to 2.29mm, but I'm not sure if that will always hold true.