OS4C-120 Copper Sealing Washers - HA194 by Hatroi  [HA194]

Sealing copper washers for OS4C-120 engines

The Hatroi HA194 copper washers are compact RC-scale spare parts intended for use with the OS4C-120 mentioned in the title. Made from copper, these washers provide a pliable sealing surface and act as spacing shims where metal assemblies need a softer interface to maintain contact and resist loosening from vibration.

They commonly function as crush or spacer washers on threaded fittings and mating surfaces in RC engine assemblies and related ancillaries. Copper's malleability allows the washer to deform slightly under torque to improve sealing and to compensate for minor surface irregularities without becoming brittle.

Installation notes: ensure mating faces are clean before fitting, replace washers that show flattening or work-hardening, and apply the appropriate torque for the specific fastener to avoid over-compression. For tuning purposes, HA194 washers can be stacked as thin shims to adjust clearance, but make changes incrementally and bench-test before full operation.