I picked up a budget metal bedframe that uses M6-1.0x45mm bolts, but there's a catch! The holes were cut poorly, so they're either a little too small or gummed up with dried paint. As a result, only about half of the bolts actually thread properly. Shipping the frame back feels like a hassle, but I remember seeing bolts with a tapered tip that might help with this. These bolts start narrower, like an M5, and then expand to M6 to assist with aligning and fixing thread issues. I'm struggling to find the right name or way to order them online. Is this type of bolt even a thing? Or do I need to look for a different solution? I've attached a mockup to clarify what I mean.
5 Answers
An appropriate tap and die set could definitely help. It’s a bit tricky though, as you might end up messing up the threads that are already there. A thread file might work too if you want to avoid messing with taps.
Just take one of your existing bolts to a hardware store. They should have a size chart to help you find bolts that fit perfectly. That's probably the easiest route!
It sounds like you're looking for a thread tap! They can help clean up and fix the threads in the holes you mentioned. Just be careful not to damage the existing threads in the process. Good luck!
Check out McMaster-Carr! They have hex head thread cutting screws that might just do the trick for your bedframe.
Why not just go to the hardware store and grab a tap and a countersink? Running the tap through the holes will make it easier for standard bolts to fit without having to spend money on special tapered ones.

Yeah, I think a thread file is a solid option for this issue!