If you’re working with thermoplastics (looking at you FDM/FFF printers!) these can be a great option when a fastened joint is called for.
As long as you have good, straight on access to the hole you are wanting to make threaded, heat sets are pretty darn easy to get a functional interface. And with some good practices and a little bit of helpful tooling accumulated along the way it gets easier and faster each time you do it.
The basic idea is that you replace your soldering iron’s tip….oh, yeah, you’ll need a soldering iron if you don’t already have one (don’t worry, it is just a tip change, so zero issue using your regular electronics’ hot pointy stick.) The replacement tip is a cylindrical post, that has an OD slightly smaller than the mininum diameter of the internal thread of the specific fastener.
The below is my go to quick reference when designing parts with heat sets. I’ve used heat sets from various companies, but have found the dimensions here to work across them equally well. I should note, I tend to be pretty conservative on the depths of holes for heat sets wherever possible. So I am less confident in the cross-compatibility claim for that parameter. But for the bore diameter and wall thicknesses I feel very comfortable designing to (kind of the “meat and potatoes” on this for me). On the conservative depths comment, it is a good idea to do so when possible, as it provides room for any overflow, etc. to move out of the way, and not build up. Getting a build up on the leading edge of the insert can quickly result in plastic getting in to and adhering to the threads.
Heat set sizing chart, from here
If you are just looking to get some inserts on hand for an occasional future need, I recommend getting some sort of variety pack like this one. Even though I tend to buy larger quantities of the sizes that I use the most (M3, M4, & M5), I continue to rebuy this set over time because I just love the convenience for one off use.
I have also bought both of these ruthex and Hilitchi assorted kits previously. While I have really been impressed with the fit and finish feel of the ruthex products in general, I still really prefer the absurdly named ‘EEEEE’ ones above :) Always nice to find examples of it NOT being ‘in a name’!
OPTION A
OPTION B
You’ll need a soldering iron/station (well, I guess you COULD use some other hot stick, but I’ll leave that to you).
These folks did a good job of showing the idea, so I’m just borrowing this…
