Author Topic: Rivet Hangers breaking?  (Read 3983 times)

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Offline Erik Sloan

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Re: Rivet Hangers breaking?
« Reply #30 on: July 06, 2014, 09:02:32 am »
Hi Josh,

Finally got time to re-read through all this stuff. Thanks for bringing this up - really, over the years I've talked to so many people about cinch hangers failing that it finally propelled me, in 2005, to dig through an old 'A5 Hammer remake' thread and find Theron's email from his post offering to help with the machining of the hammers, and contact him to start making keyhole hangers. So I'm psyched to clear up any misunderstandings I have about the strength of looped vs. cinch hangers, and any new insights we can find out about keyhole hangers. (I even made a tr about making the keyhole hangers, haha, here: http://www.supertopo.com/climbing/thread.php?topic_id=508436&tn=0&mr=0 )

Above you mention that Skot Richards test showed that #1 cable failed around its rated 480 lbs, #2 around its rated 1200 lbs(i believe), etc. But then you say that a #2 cinch will definitely hold a hard fall because it did that once or twice in your experience. I'm not trying to pick any bones, just trying to understand things here - while your 3/32s '#2' cinch might have held a hard fall once or twice, I think it's generally accepted that climbing falls can easily generate forces in the 2-4,000 lb range, depending of course on a myriad of factors, so it seems suspect to say that a piece rated to 1200 lbs is good enough to hold falls. My understanding was that the loop hangers benefited from the wire being doubled and were therefore a little stronger - a 3/32s holding around 2000 lbs, but I don't know that for sure.

What I'd be interested in is Skot testing the cinch vs the loop, and see if the loops do fail at a higher number due to the load being dispersed over a bigger area. Is Skot on here?

Offline mhudon

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Re: Rivet Hangers breaking?
« Reply #31 on: July 07, 2014, 06:47:51 pm »
Skot is going to register and start posting.

Offline S.Richards

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Re: Rivet Hangers breaking?
« Reply #32 on: July 10, 2014, 12:45:41 pm »
Yay!!!  I finally made it on here. 
Sooo.  Who would like me to test what?

Offline johnmac

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Re: Rivet Hangers breaking?
« Reply #33 on: July 14, 2014, 07:28:28 pm »
It would to great to test the breaking strain of a standard versus cinch style rivet hanger?

Offline *Mucci*

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Re: Rivet Hangers breaking?
« Reply #34 on: July 14, 2014, 09:41:37 pm »
Skot,

I can make a set of all types of hangers up to #3 for you to test if you would like?

Let me know.

Maybe make some with aluminum ovals, to show the major difference in strength achieved with the right/wrong combinations.

Will you be able to test them on a 5/16 rod or bolt with the load cell?  I have seen different numbers when cables are pulled on fat shackles.
« Last Edit: July 14, 2014, 10:43:09 pm by *Mucci* »

Offline Erik Sloan

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Re: Rivet Hangers breaking?
« Reply #35 on: July 16, 2014, 09:34:46 am »
Now we're getting somewhere. Woot!

Offline S.Richards

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Re: Rivet Hangers breaking?
« Reply #36 on: July 18, 2014, 09:04:25 am »
I'd be happy to test any set of hangers you'd like.
I'll test them as they are used in the field. Cinched around a 5/16 bolt..    I'll design some kind of test rig that will allow me to test hangers easily

Offline mhudon

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Re: Rivet Hangers breaking?
« Reply #37 on: July 18, 2014, 12:59:24 pm »
Breaking shit is fun!  :evil:

Offline rocky IV

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Re: Rivet Hangers breaking?
« Reply #38 on: September 25, 2014, 05:50:27 pm »
skot, have you tested anything? I'm interested to see how different hangers hold up in a semi realistic test...

Offline mungeclimber

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Re: Rivet Hangers breaking?
« Reply #39 on: September 29, 2014, 01:39:03 pm »

Offline *Mucci*

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Re: Rivet Hangers breaking?
« Reply #40 on: September 29, 2014, 04:41:43 pm »
That is a very dumb design.

No loop termination, so you can cinch it to the rivet, but no way you are getting it off.

It looks to be stainless steel cable = much weaker than 7x19 galv cable.

Single strand termination, is probably the worst in that design, the termination will pop right off when loaded.

I will make up some hangers for skot, just got tied up as of late.

Bottom line is you either stop due to one of your hangers catching, or it breaks and you plummet.

I have never had one of mine break in a fall, or my partners falls, and we all weigh at least 180+ lbs.

Hard for me to even consider a failure rate of a rivet hanger I make with the proper gear.  Others buy POS hardware, take falls and break them and pronounce that all cinch's are bad.  Looking at the photo linked above, I can see why we are talking failure.

I have no reservations putting one on a crucial rivet.

edited for clarity.

« Last Edit: September 29, 2014, 10:48:04 pm by *Mucci* »

Offline S.Richards

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Re: Rivet Hangers breaking?
« Reply #41 on: October 31, 2014, 08:54:00 pm »
I don't know where some of these figures ie breaking strengths come from...
I'll be happy to test any hangers anyone wants me to, in any configuration desired, with a jig and dynamometer that can measure and display the max load applied before breaking.  Bring it on. 

Offline cobbledik

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Re: Rivet Hangers breaking?
« Reply #42 on: October 31, 2014, 11:04:24 pm »
Quote
I have never had one of mine break in a fall, or my partners falls, and we all weigh at least 180+ lbs.

Ummmm, I've fallen on your cinch hangers Mucci. How DARE you claim I weigh anything more than an angel's breath above 120lbs!?! :wink:
Sometimes the difference between a layman and a journeyman is simply what he is allowed to believe himself to be.

Offline mhudon

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Re: Rivet Hangers breaking?
« Reply #43 on: November 01, 2014, 09:16:32 am »
I want to see a head to head test between a regular, loop hanger and a cinch hanger. Same diameter wire and all that. I also want to see galvanized wire against stainless.
You should take photos of the set up and before and after shots too.

Offline Rags

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Re: Rivet Hangers breaking?
« Reply #44 on: November 01, 2014, 03:23:14 pm »
Fish has some data on his site in the tech weenies section. Chris Harmston did some comparative testing a while ago.
http://www.fishproducts.com/tech/cable.html
Here's his reply -

Quote
Chris at BD writes:
I have completed the testing. Interesting.

Your standard rivet hangers are identical to loops. The cinch hangers are
half as strong as your standards. I will send you a copy of the test
report in the mail.

Quick summary.

Average data:

Loop #1 886 #2 1649 #3 2867 #5 2821
Std. #1 902 #2 1655 #3 2838
Cinch #1 577 #2 1034 #3 1453

Standard deviations range from 12 to 115 throughout all groups.

Overall these can all hold bodyweight and moderate bounce testing. I
would be a bit worried about bounce testing the #1 cinch. I certainly
would not want to fall on any of the #1's or the #2 cinch. These are
pretty strong overall though. Even the weakest are comparable to the
bending strength of most specialty small hooks.

Why would you want the largest cable sizes for rivet hangers? My guess is
that if you have a large enough rivet or bolt head you can get a stronger
piece of pro. The very few rivets I have seen would not be able to accept
the larger diameter cable???

It seems that there may be an advantage to the cinch type. They will not
allow the moving swage to release too easily. It seems to me that there
is an increased risk on the standard design for the swage to slip down and
increase the chances that the hanger will fall off the piece. I have
never used anything except small stoppers for this and have not had any
fall off either. I would be interested in your comments on these.

Hope this helps.

Chris Harmston (chrish@xxxxxxxxxxxxxx).
Be Safe, Live Long, Climb Hard!

Rick