Nitinol Titanium Split Rings

[skullpin]

Titanium is cool.

Titanium split rings that cost $5-6 each are okay.

Titanium split rings that cost $5-6 each and easily deform are not cool.

I *might* have a solution: nitinol super elastic memory metal. Nitinol is an alloy of titanium and nickel that retains the corrosion resistance of titanium and has the neat property of extreme elasticity. It seems to me that it would be the ideal metal for split rings. Nitinol is pretty expensive and the tinanium edc junkie market is pretty small, so I guess that is why no company has them on offer yet.

I came on a sample of nitinol wire that I reformed into a coil and cut up into about 30 split rings. These rings are pretty small (about 8 mm or 3/8" outer diameter) and have taken on a very nice purple heat anodizing. They are reasonably strong, comparable to normal thin gauge steel split rings, and useable for attaching gadgets to clips or to a larger ring. The photo shows two rings up close and two in the background, one on a PicoPen and the other connecting an Allox Swiss Army Knife to a McGizmo Jewel Clip.

http://www.kljworks.com/edc/nitinol.split_rings.jpg

If there is substantial interest, I will look into getting more and heavier gauge nitinol to make new rings. In the meantime, if you are interested in these, PM me. To show that there is actual interest, and to cover my efforts, I request $5 by PayPal for 2 rings sent to you to evaluate. Make it $6 if you are out of Canada/continental US. I would like to spread them around to different members to get maximum feedback, so I will only sell you two; no exceptions.


Some feedback I would greatly appreciate include:

1. Is this size and gauge strong enough for normal EDC use?

2. What is the ultimate failing strength of these rings?

3. After repeated opening and closings, do they deform?
(In normal use, they should never deform.)

4. After unravelling or other abuse, do they reform completely?
(They are able to withstand crazy abuse, but they do have limits.)

5. Does the lovely purple anodizing stand up in use?

6. How do they stand up to corrosive environments like salt water?
(They should be as corrosion resistant as titanium.)

7. Nitinol is a very hard metal and eats tool steel for breakfast. Do these rings scratch your gear in normal use?

8. Is this size of ring useful to you? Would you like to buy more in this size?

9. Are you interested in larger rings?


If interest is high, I will try first making 10 mm rings in a slightly heavier gauge. If I am successful with those, I will try making large 30 mm rings in heavy gauge nitinol. This is all theoretical at the moment, as this current crop of tiny rings were pretty tough to form. I imagine that I would need to make some special jigs for coiling heavier gauges.

Cheers, Keith

[jason.lee740]

8mm is to small for me.

I would be more interested in something that is about an inch.

[Belush2]

PM inbound...

[kpd151]

I will take two Keith. I have sent a PM with some related questions as well.

[dwong]

look cool...just the tip look too sharp.

i will take 2 to try :)

[Dizos]

Cool. Could you align them flush and taper the ends like a standard split ring?

[meeshi_ma]

I'm in for two - PM inbound.

-Brian

[jeeves3443]

reserved

[skullpin]

Some Answers to various questions here and in PM:

1. Align and flush taper? I have some ideas on this, but it would require a special bending jig to do it right. A jig that can hold the bend while the ring is being heated and reformed. For now, they will need to remain basic coils.

2. Smooth ends? They look like shark teeth in the photo, but the photo is quite magnified. One could file the ends, but beware that nitinol will wreck a good file. If I make more of these, I will get a grinding wheel and give that a go.

3. Straight metal colour? Nitinol is reformed by heating. The titanium in the alloy anodizes when heated, first to straw yellow, then green, then blue and purple. I tried a couple of yellow split rings (heated less) and they were less reformed than the purple ones; ie they were weaker. The purple could be ablated off, probably with steel wool. This would be quite work intensive and could not be done in quantity. Perhaps a tumble polisher (rock tumbler) could work... if there was humungous interest.

4. Quantity? As they are shown below, in that gauge, purple, and with unfinished ends, I definitely could make quite a few of these for cheaper.

Thanks for the interest!

Keith

[kpd151]

Thanks for answering the questions. :paypal:

[Belush2]

:paypal:

[dwong]

:paypal:

[Dizos]

1. Align and flush taper? I have some ideas on this, but it would require a special bending jig to do it right. A jig that can hold the bend while the ring is being heated and reformed.

Cool. I hope you get that sorted. What a cool product.

[skullpin]

I have been using three of these split rings for a couple weeks now to tether together a pico pen, a 4-Sevens Ti AA MiNi, and a 35mm McGizmo stainless clip. Observations:

1. The purple anodizing shows no signs of degradation.
2. These little rings are quite strong. I would guestimate their unravelling force to be in excess of 10 pounds. They are more than strong enough for keychain duty.
3. I will not be able to add a bend that will make the split ring flat. I tried and tried, and decided that serious factory equipment would be required to form a complex shape in nitinol at high temperature (>500).
4. These rings are much springier than steel and are easy to use. Putting them on thick items (like the 35mm McGizmo clip) does not deform them.
5. I will definitely grind the wire tips in the future. One split ring managed to winkle under another in pocket, and worked its way off. Grinding the tips blunt and bevelled towards the ring should prevent this from happening. Even without bevelling the tips, this should not normally happen, as these little rings would not be typically chained together.

Note to early adopters: Use a small block of sandpaper or an old metal file to do as suggested in point 5 above. Slip a plastic card between the tip and the ring to protect the purple finish. I will be sure to do this to any further rings I sell.

There are a few left. Let me know if you want some now.

I am satisfied, so I have acquired more nitinol and in heavier gauges. Will be offering more rings soon!

[kpd151]

Have the first orders shipped yet?

[skullpin]

Yup, last Saturday (except one that I did not receive a mailing address for in time). You should be getting them soon in the US.

[blackhatch]

Man i wish i had a paypal account! those look awesome man! If you have any defective ones im sure shipping would be cheap :-X

I can give em a good testing!

[skullpin]

More notes....

I am using three of these little rings to tether a McGizmo 35mm clip, a Picopen, and a Q-MiNi Ti together, as seen in the photo below. These are clipped to a ring attached to a Victorinox belt hanger (see set up here (http://edcforums.com/index.php?topic=34043)).

The ring on the McGizmo clip and Pico Pen have been secure so far. Once now, and almost twice, the Q-Mini Ti came detached. At first, I thought it was one ring winkling under another. Now I figured out what is happening: torsion. The rings are quite springy, and while strong in tension, they spring open when twisted. In this case, the Q-MiNi is relatively large and heavy, and the McGizmo clip is held firmly on the belt hanger. Torsion is frequent and directly transmitted to the ring which would open under such duress. Then, another ring would winkle underneath and eventually work its way off.

So: with this size of ring, avoid set-ups that would lead to serious torsional forces. I believe it might be peculiar to my set up, with a heavy gadget looped onto an immobile fixture. Small items (AAA lights, PicoPen, and smaller) seem more appropriately sized. Beta testers, let me know your impressions.

Cheers, Keith

http://www.kljworks.com/edc/nitinol.rings.small2.u.JPG

[skullpin]

More work from the caverns of Mount Doom...

I have made up an abundance of small rings, but now anodized blue (easier to do more consistently). I still would like to wait to see what beta testers have to say before distributing these. :)

http://www.kljworks.com/edc/nitinol.rings.small2.JPG

[skullpin]

Mount Doom forge...

An experimental one inch ring in 0.044" nitinol shown attached to an Arc AAA Ti. Different nitinol source that is "electropolished" and took on a lovely sapphire blue that did not photograph well. Reasonably strong but a little too springy. I will need to try 0.055" nitinol for one inch rings. Maybe in a couple days.

http://www.kljworks.com/edc/nitinol.ring.temp.jpg

[skullpin]

One ring to rule them all...

Or, my largest ring so far with an outside diameter of 1 inch and a thickness of 0.055". I made a single run of 10, 8 of which turned out nice and two would be "cosmetic seconds". I will keep three myself and sell the five other nice ones at $6 each which includes shipping within Canada or to the US or $7 each to (virtually) anywhere else. Again, I would like to spread the wealth and will sell only one ring to you for now. This will probably be a one off run, so get one now.

They are perfectly strong in tension, with an unravelling strength in excess of 20 lbs (estimated). Because of their springiness, they can be opened easily, and thin items can winkle their way off. Larger items with a more deeply recessed eyelet like the IAmAKey shown in the photo seem completely secure.

Some are teal, some are yellowish teal, some have purple zones, and all are unevenly anodized. Quite nice looking, but more of a rainbow effect. The anodizing is very smooth and low friction. I have lightly ground the ends so they are not too sharp and scratchy.

Send me a message if interested. And I would greatly appreciate feedback in this forum on how they work for you.

http://www.kljworks.com/edc/nitinol.rings.large.jpg

[dwong]

just got my, its very nice, i would perfer it to be a bit bigger to be more useful.

[LoM]

Size seems perfect for me. Can you send 3 of those to a european fellow EDC?

BTW, love the pico pen + quark mini solution :)

[LoM]

Have been looking for something like that for quite awhile. Im interested in 3 of those split rings, assuming its OK ordering from Europe :)

[Stix-N-Stonz]

I was looking for a ring to put MY LacieKey on, which ALSO has a TikiGod cover on it, and I've ruined 3 good rings trying to squeeze them onto that thing. maybe these will help.http://ecx.images-amazon.com/images/I/61rEkIR3z4L._SL500_AA300_.jpg

[SF1]

Any close up photos? Thanks for this R & D. Nice work, I want to have a closer look.

Best,

SF1

[SF1]

Thanks for doing the R & D on the rings? Do you have a close up photo, I would like a closer look?

Send me one, and I will shoot in my state-of-the-art studio...

Best,

SF1

[DM51]

Do you have any of these left, and if so, what sizes?

[rockingthe2]

I would be in for a couple if they were not colored and about 1-1.25"