With a quantity of two pieces, the Screw is the most used part in the 18A - BATTERY HOLDER diagram.
A sample from the products for the 18a - Battery Holder include: Battery, Holder Voltage Rectifier, Washer 6.4x16x1.5, Blackbox Unit.
The component with the lowest price in the 18A - BATTERY HOLDER schematic is the Washer.