🔧 iplusmile Brass Knurled Nuts - Threaded Heat Set for 3D Printer & Projects (100pcs, M3 Thread, 3x4.6x5.7mm) Review

I used these to put inserts in some of the 3D printed plastic parts that hold my composter together. They've been in the Florida sun for weeks and the pieces still stick together like new. The bonus is that when I broke the plastic part I was able to pull it out again with a soldering iron and reuse it for a printed replacement. I will definitely buy more when I run out. So far I've dipped them in PLA and PETG, both printed at 50% infill with no problems.

I really like these m3 inserts. Their diameter is slightly smaller than some other inserts on the market. I think that's a plus since you can place them in tighter spaces. However, if you try to use someone else's design, the modeled holes may be too large. I haven't seen how big holes these inserts fit in, but I think they work very well in a 4.0mm to 4.3mm hole. Line them up and go straight into your holes.

Pattern appears to be better than straight lines or knurling for pull out resistance and torque. The other inserts I was able to find using this pattern were much thicker, making it a little less worth using M3 screws. I measure their length 5.7mm, base diameter 3.9mm (smooth part inserted first), diameter 4.5mm. first template/knurl diameter 4.3mm between templates and 4.6mm second/last template. They melt perfectly into a 4.0mm hole, the smooth/thin section makes positioning easier and means…

I have a second bag with these inserts and love them. I've used them on both 3D printed ABS parts and PC and only had one turn (due to mis-insertion). I like that the end has a smaller and round OD which helps with centering when inserting. For ABS parts I design parts with a 4mm mortise hole. My soldering iron tip has a 2.75mm round shank with a 5mm shoulder and it presses well into plastic. No additional insertion tools are required. The outside diameter of my parts is 4.6mm, which is smaller