I used the screws supplied in the kit, a sheet metal screw about 20mm long, but as the wing tube is a little shorter than the depth of the hole in the wing I leave the tube in one wing so that when I slot it in the hole in the other side is always in the correct position, but I am at some point going to change to Neil's method I think, just as I think its a better solution, having said that I have a bout 40 flights on mine now with no issue.