Hirobo HI2539018 Hexagon Button Bolt M3 x 25 RC Helicopter Screw  [HI2539018]

Low-Profile Hex Button for RC Helicopters

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

For installation, use a matching hex driver to avoid rounding the socket, start the thread by hand when possible, and apply only modest torque to avoid stripping M3 threads in light alloy or plastic parts. If you need a more permanent hold, a low-strength threadlocker can be used sparingly while keeping removability in mind.

In routine maintenance and setup, these bolts help keep small assemblies aligned and reduce play at joins. Check fasteners after the first flights and include them in regular inspections to preserve predictable trim and control response.