Lehigh Stainless Steel Quicklink safe?

CAMP Quick links are $2.50. And they hold like 9000 pounds... I'm confused. Why is this even a question?

matt.l.b wrote: Let's see. Stainless maybe; who knows what alloy. Not forged. A single point of failure... To Metallurgy, QA, FEA, let's just lay it out... good engineering. Once again for gods sake FEA for the love of god FEA.

I have no idea what you are trying to say, but I do know that an FEA is not part of good engineering. I would laugh my balls off if someone did an FEA on a quicklink and thought it would tell them anything. Just like I couldn't stop laughing at whoever did the FEA on here of the equalized cordelette as a flat fork shaped rigid plate. That was a good one. Modern engineering education scares the piss out of me.

So I've spent a good while looking for ANY testing results for Quick Links, Rapid Links, Maillon Rapides etc etc. Either my google foo is off today or it's not as easy to find as claimed.

If someone has the link or data it would probably ADD to the topic rather than conjecture etc.

20 kN wrote: I dont know, it may have to do something with the passivation process they use, or the actual chemical compensation of the steel itself, maybe both, I am not sure. But 316 and 304 classifications do not site specific competition requirements, but rather a range. So 316 SS can contain between 10 and 14% nickle and 2-3% molybdenum, for example.

In that case, what's your basis for making the statement in the first place?

mattm wrote:So I've spent a good while looking for ANY testing results for Quick Links, Rapid Links, Maillon Rapides etc etc.

Had a friend who tested two cheap 1/4" links, both plated carbon steel. They broke at 6100 lbf and 6200 lbf.

Bump up to 5/16" or 3/8" and you'd have to find someone with a load tester that has a capacity above 10k lbf, methinks, and, those aren't easy (or cheap) to come by.

Nice thing about buying stainless rapides, is, you can kinda tell that at least they're 300 series stainless (as opposed to plated carbon steel, or, 1018 or some such). They also take paint better.

I use the cheap stainless ones with abandon. Usually paired with a Fixe rappel anchor, or, in pairs. Never as the end rappel point. I match them with a stainless Fixe ring. Not worried about them getting thin with wear that way, or, having to replace them if/when they get grooved out.

Inexpensive CAMP ones are plated I seem to recall.

mattm wrote:So I've spent a good while looking for ANY testing results for Quick Links, Rapid Links, Maillon Rapides etc etc. Either my google foo is off today or it's not as easy to find as claimed. If someone has the link or data it would probably ADD to the topic rather than conjecture etc.

My results used to be posted over on RC, but they were removed when I left the site. Should be enough quoted material to make finding it easy, so my guess is your GoogleFoo is off today. Short version of the first round of testing: 6 samples stamped 1550#WLL, mean breaking strength of 5278#, standard deviation of 435# and 95% confidence level of 4821-5734#. All broke by way of the threaded section failing. I did a bunch more after that, but would have to go digging for the results.

Aric Datesman wrote:My results used to be posted over on RC, but they were removed when I left the site. Short version of the first round of testing: 6 samples stamped 1550#WLL, mean breaking strength of 5278#, standard deviation of 435# and 95% confidence level of 4821-5734#. All broke by way of the threaded section failing. I did a bunch more after that, but would have to go digging for the results.

What size?

I don't remember off hand, as this was years ago and they weren't my quicklinks. I simply had an email handy that had some of the numbers.

EDIT- Scratch that, just found a copy of the full results. They were 5/16", stamped "5/16 SWL 1550" and tightened finger tight.

Failure loads were:
Sample 1: 5472 lb-f / 24.34kN
Sample 2: 5120 lb-f / 22.77kN
Sample 3: 6048 lb-f / 26.90kN
Sample 4: 4831 lb-f / 21.49kN
Sample 5: 5212 lb-f / 23.18kN
Sample 6: 4986 lb-f / 22.17kN

Petzl 1: 6895 lb-f / 30.67kN
Petzl 2: 6901 lb-f / 30.70kN

Here's a pic to show the difference in failure modes, with the Chinese quicklinks having sheared threads and the Petzl ones having the top or bottom come off:

Another set of tests had them tightened with a wrench. 400in-lb put them at ~finger tight + 1/4 turn, 500in-lb put them at ~finger tight + 1/2 turn.
Sample 1: tightened to 400 in-lb @ 102 degrees rotation from finger tight. Threads on bottom of body sheared off @ 5808 lb-f

Sample 2: tightened to 400 in-lb @ 93 degrees rotation from finger tight. Threads on bottom of body sheared off @ 5442 lb-f

Sample 3: tightened to 400 in-lb @ 123 degrees rotation from finger tight. Threads on bottom of body sheared off @ 6386 lb-f

Sample 4: tightened to 400 in-lb @ 102 degrees rotation from finger tight. Threads on bottom of body sheared off @ 5920 lb-f

Sample 5: tightened to 400 in-lb @ 85 degrees rotation from finger tight. Threads on bottom of body sheared off @ 5697 lb-f

Sample 6: tightened to 500 in-lb @ 119 degrees rotation from finger tight. Torsional yielding evident on body just above shoulder nut closes onto, shoulder rotated ~25 degrees in relation to body. Threads on bottom of body sheared off @ 4969 lb-f

Sample 7: tightened to 500 in-lb @ 171 degrees rotation from finger tight. Threads on bottom of body sheared off @ 5808 lb-f

Samples 8 and 9: broke before reaching finger tight + 1/2 turn, so tested as an open quicklink. Sample 8 opened up enough to let the carabiner slip out at 965 lb-f, Sample 9 at 981 lb-f.

Sample 10: tightened to 500 in-lb @ 180 degrees rotation from finger tight. Severe torsional yielding evident on body just above shoulder nut closes onto, shoulder rotated ~90 degrees in relation to body. Threads below shoulder sheared off @ 5253 lb-f. Last sample tested, so pulled to end of stroke on puller for kicks and giggles. It was actually still holding onto the biners like this, needing probably another 1/4" of stroke to finally pop off. Oh well.

Great stuff!

Do you recall if they were stainless, or, plated?

Thanks!

Looks like they were plated and sourced from here: stageriggingonline.com/chai…

The guy who bought them (tradklime over on RC) was planning on using them in pairs on rap stations.

Oh, one further piece I neglected to mention- Per Petzl's documentation their GO Maillon Rapide (it's the one with the 7mm diameter spine- petzl.com/en/outdoor/vertic…) should be tightened to 2.5Nm, which is ~1.84 ft-lb (22.1in-lb) and much, much closer to finger tight than finger tight +1/4 turn .

rmsusa wrote: In that case, what's your basis for making the statement in the first place?

Because I was asked a question, so I responded. But the information I said in my previous post is accurate, the passivation process is important and Fixe's links are obviously superior in that regards.

20 kN wrote: Because I was asked a question, so I responded. But the information I said in my previous post is accurate, the passivation process is important and Fixe's links are obviously superior in that regards.

Not to point out the obvious, but you seem to have missed his point: the only part of your response that you were qualified to comment on was the first three words. Everything past that point is complete and utter conjecture, as metallurgy is far from anything you have more than a slight layman's familiarity with. Seriously, please stop speaking authoritatively on subjects you know nothing about.

aric's numbers are pretty similar to test results of 5/16" quicklinks from a recent project i worked on. i usually use a pair of them, or sometimes 3/8" links at anchors on routes.

I think it should be stated that there are two distinct applications being discussed here. Both for a standard TR application, and a fixed rap station, quicklinks (always used in pairs) are generally stronger than the rope itself. Keep in mind, a system is only as strong as it's weakest link.

• Most ropes have a strength rating of about 10kn (assuming 9.8mm with 8-9 UIAA fall rating)
• Those of you who stated that a quicklinks SWL (safe working load) was 1/3 the breaking load, your right. (depending on the country the product will be sold in) Even in the links made in China are batch tested (albeit NOT as rigorous as climbing equipment is tested) to the standards set forth by the country they are to be sold in. the US requires SWL to be 1/4 the batch tested breaking strength. So a 5/16" quicklink, as shown in the photo, has a SWL of 1540 which means the tests came in at 6160 at the factory (not too far from the apparent average shown in the photo.)
• In short, even without the 4x actual strength, two 5/16" quicklinks are rated in tandem at 13.8kn. a full 855lbs stronger than a standard rope. (I know some ropes are stronger).

Why we climbers tend to over analyze everything these days is really quite perplexing. It would do us all some good to remember that Yvon Chouinard made his first pitons out of old stove legs, and we see him and his ingenuity as a legend in our sport.

I for one am not ready to chastise somebody for using quicklinks in either application. Good judgment and sound placements are far more important than the logo on your biner (or lack of one on your quicklink). Like any rig, it's only as good as the climber who placed it.

Kevin Rogers wrote: *Most ropes have a strength rating of about 10kn (assuming 9.8mm with 8-9 UIAA fall rating)

Uh-oh...

Gunkiemike wrote: Uh-oh...

Aww shit.