Yaocom 300 Pcs M3 Threaded Inserts M3 x D5 x L4 Heat Set Inserts Brass 3D Printing Knurled Metric Nuts for Plastic, 3D Printing Components

They work perfect for 3d printing! I've ordered then numerous times and haven't been let down yet.

Perfect to size and work as intended.

As expected. They stay in well. Same spec as the ones that come in VORON kits.

used for a battery

they work well, and have great sticking power i guess you would say. I'm not putting heavy duty items together but it works well

These are great. They work great for melt in threads. My prints are now stronger and screws are less likely to strip out. I only tried it with PLA but I assume ABS would work just as good.

Seem to be pretty good quality. Engages well with the M3 screws I have, and heats up fine with my insert tool. 300 will last a long time.

They work well. I think out of 40 or 50 inserts only messed up one and it was my fault.