Hardware

RC screws are metric. You need the diameter (M2, M3, M4 etc), length, and head type (cap head, button head, countersunk). Your car's manual lists every screw by size, or use the parts finder to look it up by model. If in doubt, pull out the old screw and measure it with callipers.

Almost all hobby RC cars use metric fasteners. The only common exception is some older HPI or American-made vehicles. If your hex driver slips, you've probably got the wrong system — try the next metric size up or down.