Hirobo HI2539018 Hexagon Button Bolt M3 x 25, RC helicopter screw  [HI2539018]

Hexagon Button Bolt for RC Helicopter

This M3 x 25 hexagon button bolt is an RC-scale fastening part intended for helicopter assemblies and other small model fixtures. Its low-profile button head sits flush against thin plates and brackets, making it suitable for frame joins, rotor mount brackets, and similar locations where head clearance matters.

Installation is straightforward: use a matching hex driver to avoid rounding the socket, start threads by hand when possible, and tighten to a modest torque to prevent stripping M3 threads in lightweight alloy or plastic parts. If a more permanent hold is required, a low-strength threadlocker may be used sparingly, remembering that frequent disassembly will require a removable solution.

In tuning and maintenance, these bolts serve a simple but important role: they keep small assemblies aligned and reduce play at connection points. Inspect fasteners periodically for loosening after initial flights and retighten as part of routine checks to maintain predictable trim and control response.