M4 Brass Knurled Threaded Insert

These M4 Brass Knurled Threaded Inserts are heat-set fasteners designed to add strong, reusable metal threads to 3D printed and injection-molded plastic parts. Ideal for hobbyists, makers, and engineers working with PLA, PETG, ABS, and similar thermoplastics, these inserts solve the common problem of stripped or worn-out threads when screws are driven directly into plastic. Installation is simple: using a soldering iron or heat-set tool, the insert is pressed into a pre-drilled or printed hole, melting the surrounding plastic so it flows around the knurled body and locks the insert permanently in place once cooled. The double-helical knurled exterior maximizes grip and pull-out resistance, while the brass construction offers excellent thermal conductivity for fast, clean installation along with long-term durability and corrosion resistance. These inserts are perfect for enclosures, brackets, robotics projects, RC builds, and any application where parts need to be assembled and disassembled repeatedly without degrading the plastic threads. Available in multiple length options to suit different boss depths and part thicknesses, this range gives makers the flexibility to choose the right insert for shallow or deeper mounting points while maintaining a consistent, reliable M4 thread across all sizes.

Specification:

• Thread Size : M4 x 0.7mm
• Outer Diameter : 6mm
• Material : Brass
• Knurl Type : Double-Helical Knurled
• Installation Method : Heat-Set (Soldering Iron or Heat Press)
• Compatible Materials : PLA, PETG, ABS, and Other Thermoplastics