A ball bearing guide refers to a component used together with a router’s cutting edge to get smooth and precise cuts. The ball bearing guide is an enclosed wheel-like casing which is attached to a bit-spindle or shank on the router. Just like the name implies, a ball bearing guide rolls like a wheel and steadies a router when placed on an edge surface or jig while cutting. A ball bearing guide is vital to ensure a steady and steady cutting session while working on finishing and moldings. There isn't a standard size for a ball bearing guide. Rather, the size is determined by the relative location of the bearing and the size of the cutting bit.

 

Certain bits come with a small bearing which aids in cutting edges or moldings. The bearing is usually present below the cutting tip, and when present at this location, it serves as a horizontal depth gauge. Alternatively, if the small ball bearing is present above the cutting tip, it acts as an important guide for deep multiple-pass cuts. However, its usage is limited to a certain depth. Once you notice the ball bearing guide doesn't rotate freely, ensure you replace it instantly with another of the same size to sustain its effectiveness.