Best indexable inserts according to redditors

The part you have called a washer, isn't, it is the flange of the rivnut that is now spinning in the seat tube as it has lost clamp force.

Try u/twodogsfighting suggestion and use an impact gun (if you have one) to remove the fastener, if it won't come out, you can try a small amount of cyanoacrylate (super glue) to see if you can get it to wick into the joint and hold enough to allow the fastener to be removed.

If this doesn't work, then you will have to utilise a destructive method. Starting with the plastic bottle cage, to gain access to the rivnut, then try placing a screwdriver between the fastener and the rivnut and twisting to lock the nut, then impact the fastener out.

If there is room, you may be able to grab the rivnut flange with pliers or vise-grips, then undo the fastener.

Last resort, cut the fastener and grind of the flange of the rivnut and then retrieve the remains by removing your seat post.

Take the frame to a bike shop to have them install a new rivnut, unless you want to invest in the setting tool

Good Luck

There are smaller internal threading tools, I have seen ones that hold carbides down to 5mm, but with everything they are still around 1/4" minimum hole size. You can also find some from thinbit.com, they have a line called microbit that can get really small, from their website "For internal diameters of .077" and larger. ". Amazon has some of them like https://www.amazon.com/MICROBIT-Uncoated-Carbide-Threading-Elliptical/dp/B01MTIZ8W3 and the price isn't horrible, but be careful to follow the recommended feed and speed suggestions, would hate to break one. If you search "thinbit" you can find other offerings too.

One other option is cut an external thread and make a tap that matches what you want and tap the hole.

If you make your own, a good reference is https://sct-usa.com/wp-content/uploads/2015/08/Catalog2015_081015_QUALIFIEDTHREADTOOLS.pdf, this is also an option instead of the microbits above, but I haven't seen prices of these tools.

OK, going to leave the above info, but was looking around Amazon and found the "Micro 100" line, search for "Micro 100 single point", the price is right, and you can get a good selection of sizes. I think this might be the way to go. Here is an example https://www.amazon.com/Micro-100-Internal-Threading-Projection/dp/B00Q8M1HQ0 but look around to get what fits your needs best.

Thanks for the question, I have ordered a couple of the Micro 100 ones to try out, as I hadn't seen them before and they look really nice for the job.

Like these https://www.amazon.com/dp/B07G386Y3B/ref=cm_sw_r_apa_i_-ELLDbZSCDGA5

The rods come painted or something, and seldom come with instructions to scrape the coating off before use. It would be good to carry a few cheap rods in your environment to see if the coating is effective. You can get like 5 rods - 8mm thick on Amazon for a few dollars. To me that makes sense to keep one to play with, and one unused out of the same lot to keep in reserve (and a few lighters too)

>I'm looking to switch to a flint/steel or flint/titanium setup for my backup. Just wondering if anyone knew of a good modern alternative to flint?

Uh, any silicon based rock? Quartz? Chert? I guess you might be limited as to what you can find in your area. A tungsten-carbide lathe tooling insert link for photo, not an endorsement might work on steel or titanium and meets your criteria for "modern alternative". An impractical modern alternative is a battery powered angle grinder.

(Tungsten-carbide works great on ferro rods, but anything hard and sharp works on them, it's a low bar.)

So it's important to note that with flint/steel or flint/titanium, the metal is the thing that is generating the sparks, not the flint. That's opposite of what's going on with a ferro rod. You can use a knife or broken chunk of glass, or nearly anything hard to scrape the rod, and it's the rod making the sparks.

The sparks struck off a steel are much less hot than a ferro rod. Titanium is better than iron, but still doesn't give you the shower of sparks you get from a ferro rod.

Sounds like you're looking for an internal retaining ring (or O-ring) grooving tool. These have carbide cutting edges, and come in different profiles so you can cut the proper shaped groove for your O-ring or retaining ring, e.g., square shaped slot, v-shaped, half-round, etc. Try a Google search for "internal retaining ring grooving tool" and you'll find enough to help you get started finding what you need. Here's a link to one on Amazon as a start:

https://www.amazon.com/Micro-100-QRR-039-16X-Retaining-Projection/dp/B00Q8NR718/ref=sr_1_12?gclid=CjwKCAjwk7rmBRAaEiwAhDGhxBH-hio7eC3-DCH1OsZ3_IEoA2OA8NjA8M-hxPeznLraCYKp8uteNRoCcCQQAvD_BwE&hvadid=323144562441&hvdev=c&hvlocphy=9003944&hvnetw=g&hvpos=1o2&hvqmt=b&hvrand=13326339003767944250&hvtargid=aud-676677759484%3Akwd-527024404990&hydadcr=28602_10166550&keywords=retaining+ring+grooving+tool&qid=1557111657&s=industrial&sr=1-12

I bought a set of carbide tools from ebay and turned the handles myself. It was a good first project and I have something I am proud of. That said, my local shop sells a lot of these and they recommend them over more expensive tools to start out. https://www.amazon.com/Rikon-Four-Piece-Turning-Carbide-Inserts/dp/B078XLQ3TM

I keep a Carbide Turning Tool Holder in my car,RC for just these kind of people, does a lot of damage to a car.