The Screw-washer,4x12 is the cheapest item from this partsfiche.
A sample from the products for the Servo Motor include: Bolt-washer,6x28, Nut,flange,6mm, Collar,6.3x12.5, Screw-washer,4x12.
With a quantity of two pieces, the Rubber,mountting is the most used part in the SERVO MOTOR diagram.