Ballraces are used wherever moving parts are required to run with a minimum of play and a minimum of friction. The more ballraces are used, the more smoothly the mechanics of a helicopter works, and the lower the rate of wear.
The dimensions of a ballrace mean:
inside diameter (I.D.) x outside diameter (O.D.) x thickness.

• Ballrace 10 x 21 x 5 mm
• pack of 1

Important: The inner ring of a ballrace (in roll-axis levers, mixer cranks etc.) must be free to rotate. Shim washers are used to provide clearance where necessary. Shim washers are also used to compensate for excessive clearance which may result when tolerances accumulate.