Hudy 3.5mm Arm Reamer
Hudy recently released this new Arm Reamer which has been designed specifically for R/C use, and will precisely resize plastic holes without creating excessive slop, allowing you to build a perfect free-moving suspension. The tool is specially designed and hand ground to create sharp micro edges on the surface of the tool pin to precisely size plastic without tearing, stressing or over-sizing the hole of the suspension arm.
Source: Hudy [hudy.net]