Kadrick 520Pcs M2 M3 M4 M5 Threaded Inserts Assortment Kit for 3D Printing Components, Metric Brass Knurled Nuts, Insert by Heat into Plastic Parts

The media could not be loaded. Works just as expected and no issues with setting them using a soldering iron. Case is sturdy enough but I'd keep a rubber band around it just incase, would hate to have it accidentally open and try to pick up all the inserts. Only have tried the m5x10 and it worked perfect with my m5 bolt that I used. Great value for the money and good variety to test out. Will refill with the same brand as needed.

Good selection.

I have used these on a number of 3D prints. They work best when used with a soldering iron with tips designed for inserting this type of connector. There is a learning curve on how to use these correctly, but once you figure it out, it works well and I don't mess up too often.

This 520‑piece Kadrick kit gives you M2–M5 brass knurled inserts plus heat‑set tips—perfect for adding durable, metal threads to 3D prints. The kit includes a tool and labeled compartments, making it easier than buying parts separately.Installation is straightforward with a soldering iron or compatible tip: the inserts seat cleanly and grip well. Most inserts hold torque and don’t spin under screw loads once installed.Great value if you frequently need threaded holes in plastic—just follow the recommended hole sizes for best results. Expect reliable performance for hobby‑tier projects.

Exactly what I ordered.

Works great

These are good inserts for the price. They don’t spin when a torque is applied to them, and they are easy to install correctly. Just use the hole size listed for the smaller diameter and it fits like a glove. Also, make sure you use enough perimeters around the hole to ensure it’s good strength. I usually do a minimum of 4 perimeters around the holes.

I needed a variety pack to see how big they were and what sizes would fit for my project. In the future I will just buy more of the size that I need, if I run out of these. They are of good quality and work as expected.