ruthex 1/4" Threaded Inserts - 20 Pieces RX-1/4“-20x12.7 Brass Heat Set Insert for Plastic Parts - Inches knurled Nuts - Insert by Heat into 3D Printing Components

Impressive. Worked very well, easy to press in. Threads nice and clean.

Great product. Works as intended. Easy to heat with a soldering iron. No special tip required, just a large cone tip.

Buy these, no matter what. You’ll regret buying from others, promise. I use thousands of these for my products for customers. They are essential to my business. I recently tried to buy another brand that was a little cheaper and it was a bad mistake. About half of them have damaged or defected threads, but you don’t know until after you try a screw in them. This has caused me many failed prints, a lot of money wasted. All because I tried to save a few bucks. I will never go to any other brand, this is literally the only one I trust. I don’t leave reviews, but after the nightmare with the other brand that starts with a U, I felt it was imperative I help out others. Don’t buy anything else.

I used them for inserts on cabinet doors and drawers and then epoxied 8/32 flat head machine screws to river rocks, nice pulls for under 20 bucks. Stainless steel tubing to cover threads.

Let me just say this—if you’re printing enclosures or mounts and not using threaded inserts like these… you’re playing life on hard mode. I’ve burned through enough 3D prints to know that tapping straight into PLA or PETG is like trusting a paper towel in a hurricane. That’s where these ruthex M3 inserts come in and save the day like some kind of tiny, brass-threaded Avengers. These things heat-set like butter. No deformation, no bulging, no “oops, pushed too far” drama. The knurling bites in just right, and they seat clean at the recommended temps. I used a Weller iron with a blunt tip, hovered around 210–220°C, and every single one went in textbook perfect. No cracking, no misalignment. They don’t back out when you unscrew either. I’ve tested that plenty—over-tightening, removing and re-seating a half-dozen times—and they still hold strong like it’s their first day on the job. And the RX series? 👌 These aren’t your dollar-store “sorta fits” inserts. These are precision made. Consistent sizing, clean threads, and they ship in a plastic box that doesn’t explode open like it’s trying to test your patience. What I Like: Insertions are clean, controlled, and oddly satisfying No burrs or malformed pieces—every single one was usable Threads hold torque like a champ, no pull-outs ruthex isn’t playing around—these are real-deal engineered, not sketchy mass-stamped junk What Could Be Better: Honestly? Include a small tool or press-fit guide for new users maybe. That’s all I got. Oh, and maybe a reminder that yes, they are hot after heat-setting (ask my thumb) TL;DR: If you’re printing anything that needs to be unscrewed more than once, stop relying on melted plastic holes and upgrade your builds. These ruthex M3 inserts are rock solid, heat-set clean, and make your prints look and feel pro. Your future self (and your screwdriver) will thank you.

Worked like a charm in my 3D printed roses. Installed them with a soldering iron. Used 6. No idea what I'll do with the other 94, but maybe I'll make a case for something one day...

Quality inserts, but the case came with no latch to keep it closed, so It's pretty much useless.

I've never had any trouble setting these with my soldering iron. I don't use any additional tools, jigs, or presses. Pretty easy stuff They work well and don't come out. Big fan