So, I need to screw my coopered seat to the undercarriage of a set of chairs I'm making. The seat is elevated above the undercarriage by 4 standoffs that will be through drilled to allow the screws to pass through, and move with seasonal wood movement. But there can only be 4 screws. So, do you think I can get by with #10 screws or must I step up to #12's? The seat is butternut.