Hexagon Button Bolt M3 x 4 Hirobo HI2539023 Screw for RC Helicopter General Parts  [HI2539023]

Thread and Fit Guide for M3 x 4 Button Bolt

This is an RC-scale hexagon button bolt supplied as Hirobo HI2539023, intended for use in helicopter general parts and small-assembly fastening roles. The M3 x 4 code specifies a 3 mm thread and 4 mm length, a common standard for model helicopter joints and attachments.

When fitting, hand-start the thread to ensure proper alignment then tighten with a suitable hex driver without over-torquing. The bolt provides a secure, low-profile connection for linkages, mounts, and small brackets within rotorcraft models.

Confirm the target component accepts M3 x 4 fasteners and check clearance and thread engagement before completing installation to assure a dependable fit in your RC model.