Do not use these for the X1 rear axle clamps, they will break off in a hard crash as I did in a Las Vegas carpet track crash in practice. I highly recommend using a non aluminum version M3 screw, much more reliable. The few grams you save with this is not worth it
Strength" Flat Head Screws from ProTek R/C. These are made from metric grade 12.9 steel which has a minimum tensile strength of 174,000 PSI. These screws are the strongest you can get ...