For our purposes we've found older Lowe screws work great for snowkite. They are a wide diameter screw which makes for easy clearing after you've taken the screw out. Especially important if you only have one screw.
We always have 2 screws. One that we leave at the launch area with a flag in it and one on board for emergency kite landings out and about. If you never fly far from where you laun
ch one screw will do.