4.1 x 5.1 x 0.1T Hirobo HI2506065 Flat Spacer for RC Helicopters  [HI2506065]

Washer application notes

This Hirobo HI2506065 flat washer is a low-profile spacer intended for helicopter and general RC parts assemblies. The stamped dimensions 4.1 x 5.1 x 0.1T describe inner diameter, outer diameter and thickness, which suits use where minimal material thickness is required to alter clearances or correct alignment between mating parts.

In workshop tuning the washer is used as a micro shim: inserting or removing a single 0.1T washer will change shaft endplay, bearing preload or gear mesh by a slight but noticeable amount. As a flat washer it provides consistent contact across a bearing seat or fastener head to keep loads even and reduce lateral play.

Installation guidance: handle the washer as a precision spacing component, check orientation where relevant, and only stack washers per assembly tolerance guidelines. For tighter fits, choose small step changes to keep drivetrain balance and part alignment intact.