Brass Knurled Insert Nut M1.6–M6 — Heat Set Threaded Embedded Nut for 3D Printing & Injection Molding

Brass Knurled Insert Nut M1.6–M6 — Heat Set Threaded Insert for 3D Printing & Injection Molding

Brass knurled insert nuts are the professional solution for adding strong, reusable metal threads to 3D printed plastic parts. Using a soldering iron or heat-set press, the brass insert is pressed into a pre-drilled or printed hole in PLA, ABS, PETG, nylon, or injection-molded plastic. The knurled outer surface bites into the softened plastic as it cools, creating a pull-out and torque-resistant threaded connection that far outlasts plastic threads alone.

Key Specifications

Why Use Brass Insert Nuts?

• Metal threads in plastic — Brass threads handle repeated assembly/disassembly cycles without stripping, unlike tapped plastic threads
• Knurled grip — The knurled outer surface locks into the plastic matrix for high pull-out and torque resistance
• Heat-set installation — A standard soldering iron at 200–250°C melts the plastic around the insert for a flush, secure fit in seconds
• Wide size range — M1.6 through M6 covers the full range of fastener sizes used in electronics enclosures, robotics, and mechanical assemblies
• Reusable — Screw and unscrew as many times as needed without wear to the insert threads

Installation Guide

• Design or drill the hole to the recommended diameter for your insert size (typically insert OD − 0.1mm to 0.2mm for heat-set)
• Heat your soldering iron to 200–250°C (lower for PLA, higher for ABS/Nylon)
• Place the insert on the hole opening and press gently with the iron tip
• Apply steady downward pressure until the insert is flush with or slightly below the surface
• Remove the iron and allow to cool for 30–60 seconds before applying load

Frequently Asked Questions

Q: What hole diameter should I use in my 3D print?

For heat-set installation, the recommended hole diameter is typically the insert outer diameter minus 0.1–0.2mm. For example, an M3 insert with 4.6mm OD works best in a 4.4–4.5mm hole. Refer to the Voron Design or CNC Kitchen insert guides for specific recommendations by insert brand and plastic type.

Q: Can I install these without a soldering iron?

Yes. Press-fit installation is possible in softer plastics (PLA) by applying firm pressure with a flat tool. However, heat-set installation provides significantly better pull-out strength and a cleaner flush finish.

Package Contents

• Pack of brass knurled insert nuts (size and quantity per selected variant)