Swpeet 370Pcs 4 Values M2 M3 M4 M5 Female Thread Knurled Nuts Brass Threaded Insert Embedment Nuts Hydraulic Welded Joint Injection Molding Assortment Kit Perfect for 3D Printing Injection Molding

I was hesitant to get these because I was looking for ones that had more holding edges. I didn’t know if these would hold that well, but they had 3 of the sizes I needed immediately so I gave them a shot. They hold well. And yes I was pleasantly surprised. I actually created two pieces that if these twisted or came out I wouldn’t waste the parts I’d already printed.I’ll keep using these unless they start slipping, though it appears the PLA+ I’ve been using melted around them quite well.

I use these inserts quite a bit, I am a prolific 3d printer nerd! If I need something and it can be 3d printed then I will 3d print it. Not only does this save me money but also gives me a warm fuzzy feeling that I haven't had to go out and spend my hard earned money on something I could have made. These inserts are awesome because they now give me the ability to insert proper sized threads into my 3d prints instead of drilling and tapping the plastic and hoping is wasn't going to strip out. What I like so much about them is that once they are heated up with tip the soldering iron, I can push them into place and the plastic printed part melts around them and then hardens, securely holding them in place by the ridges and BINGO, I have a perfect thread exactly the right size and exactly in the right place. These threaded inserts are also a very competitive price and you get a whole load of them of many different sizes. If you have need of something like this, buy them, you wont regret it, they are very good quality.

Chances are if your DIY part fails under load, it won't be at the brass inserts. Just get these

Somewhat necessary if you want to make an assembly out of 3D printed parts. They do exactly what they should and hold well. The trick is learning how to push them into your part. Using a soldering iron tip to heat it up and position it and then pressing it in with a flat surface that will go flush with the part is the best way I've found.