Tamiya TRF420X Stiffener Nut 9803402 for Hop-Up Assemblies  [9803402]

Role and compatibility of the stiffener nut

This Tamiya 9803402 stiffener nut (part no. 42382) is an RC-scale threaded fastener intended for TRF420/TRF420X hop-up assemblies. It secures chassis stiffener components and helps retain preload and alignment when tweaking chassis stiffness. The text highlights compatibility and tuning purpose rather than dimensional specifications.

In use the nut provides a locking or reinforcing point for a stiffener plate or brace in the chassis layout. When you swap stiffener plates, fit reinforcement inserts, or experiment with chassis flex, the nut holds the assembly location and reduces unwanted movement that can affect handling balance. Follow normal workshop practice for tightening, avoid over-torquing near thin aluminium or composite parts, and check mating threads and seating surfaces when reusing hardware.

For model builders concerned with fitment, this nut impacts mechanical connection points rather than altering suspension geometry or electronics. Keep spare fasteners available and inspect threads regularly if you change hop-ups frequently.