Bill, We routinly install turret style terminals into both plated thru holes and into non plated thru holes without pads on both sides. The only difference is the style of rollover used. In plated thru holes, or on holes with a pad on the clinch side of the board we only flare the terminals. In holes where there is no pad or electrical connection on the clinch side of the board we use a rollover to allow the terminal to get a better bite into the board.