QSJ 130Pcs Threaded Inserts Heat Set Inserts Kit M3x4x5 Brass Insert Nut with Soldering Iron Tip for 3D Printed Plastic Materials

i bought these for a few random projects i had or will have so it just sat in my drawer, soldering iron tips and everything. but when i needed these inserts oh boy did they work beautifully.i don't have the most professional soldering iron but the soldering iron tip this comes with fits great and fits the little inserts good enough for me to melt them into whatever i needand once ive melted them in, boy do they grip. the inserts are tough and tight in the plastic, and it's easy to use to screw in whatever you need. the example i bought a plastic shotgun stock that came in a pretty poor state, where the buttpad was supposed to screw on and there was no hole for the screw. come in these little inserts, went in nice and smooth and worked with my junk drawer mlok screws for a quick, cheap and solid fix, the few dollars i paid for these inserts actually made my shotgun stock worth it's price which is a win.

First time I have used these. They are a good fit on the M3 screws as selected. They seem to hold well and overall a nicer solution that screwing into the bare plastic.

As expected. Size was true. Set and held well in my 3d models

This worked perfectly for my 3D printing project. its a nice assortment of sizes. it has the soldering iron so you have everything your need to use it

Not sure what more you could need or expect from brass heat-set inserts.

These threaded heat inserts are excellent—well-made, reliable, and easy to install. They heat-set cleanly into plastic with no warping or cracking, and once in place, they hold strong, providing a durable, professional-grade thread that’s perfect for repeated use. A solid product that adds real value to any build—highly recommended for makers and professionals alike.

These have worked great so far to add some machined threads to my 3d prints. I love that in includes a purpose built tip so I don't have to worry about ruining any of mine.