https://www.facebook.com/zaadventure/posts/464185190440263
From somehwere foreign  :-[ but you get the idea - check fixed aids before use!

In English I still Can't understand!

A picture is worth a thousand words!

[2016.05.07 - Dangerous Cave Rock tied detection] this day very happy, ZA instructors at super good weather, to assist in detecting dangerous cave rock tied, also check to several dangerous rocks on the route of the first outer corner tied! I hope you pay attention to in addition to rock climbing safety, can also support at Cave Re-bolt plan.

The main image - cant work out how to resize...

ZA Adventure are a Taiwan group so I guess the crag in the photos might be Long Dong which is a sea cliff. There have been many reports of anchor failures at tropical sea cliffs. There is a lot of information on the internet about stress corrosion cracking of anchors in those places.

https://www.thebmc.co.uk/bolt-corrosion-warning-from-the-uiaa

By the way - it isn't a bolt. Bolts have a thread and go with a nut.

Oh dear.  Presumably they were testing it and it failed within the metal.  The shape of the head implies a low failure load (the Colinox head deforms above roughly 20kN).  They were using a Hydrajaws tester which I beleive is only good for up to 30kN according the the Hydrajaws web site.  The failure mode possibly looks like a small mount of ductile before a  brittle failure.  The relatively small amount of testing I have seen of Petzl Colinox anchors (a few tens) have not failed in the metal.  I have also tested two Batinox anchors to 30kN without metal failure (in a tensil tester whilst calibrating a load cell).  Petzl claim Colinox and Batinox are good for 50kN axial pull in a suitable matrix.

I guess it is reasonable to speculate some form of corrosion.  The images do indicate some brown staining or perhaps corrosion.  Chloride Stress Corrosion Cracking is one reason why BCA E&T don't like using anchors with welded heads.  Though Colinox and Batinox are forged so the problem should be much less.  I am not sure but I think both Petzl anchors are made from 316 Stainless Steel which if the placement is on a sea cliff (as seems to be the case from one photo), would not be a good location for 316 anchors, never mind 304 SS.  See also http://www.theuiaa.org/news-316-New-Download-UIAA-Warning-About-Climbing-Anchor-Failures.html 

But I do worry that the main image shows the characters '25 K' on the head; I don't recall seeing those characters on the Petzl anchors I seen.  (The heads I have seen have the words "Petzl Colinox" or "Petzl Batinox" on one side with "Stainless Steel" on the other.)  Which raises the question is this a counterfeit anchor? 

Bob Mehew said:

But I do worry that the main image shows the characters '25 K' on the head; I don't recall seeing those characters on the Petzl anchors I seen.  (The heads I have seen have the words "Petzl Colinox" or "Petzl Batinox" on one side with "Stainless Steel" on the other.)  Which raises the question is this a counterfeit anchor? 

Click to expand...

Genuine Petzl

Genuine Petzl?

https://www.petzl.com/GB/en/Professional/Anchors/COLLINOX#.VzDlFOSgyVQ

http://adventureropegear.com/cart/

From their site. Take it up with them.

Plenty of retailers selling Petzl Collinoxes with the 25k marking



https://www.google.co.uk/search?q=petzl+collinox&client=firefox-b-ab&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjlk6qk383MAhWrK8AKHcidB7YQsAQIKg&biw=1150&bih=657#imgrc=_

Yep - major issues in hot humid far east sea cliffs like Thailand and Vietnam etc.  Well publicised. 

This is why Titan bolts have set up making titanium bolts. 

http://www.titanclimbing.com/why.html

Not really an issue in UK caves though.

It is a problem for anchors in the sea cliffs above some caves which is why E&T and DCUC are searching for an alternative to 316 anchors.  We think we have a suitable product subject to confirming a few details.

Thanks Cap'n Chris for the correction, my Petzl web site gave no such 25K images so I went by those I had photos for. 

I understand Titanium wears rapidly if used for pull throughs ,unfortunately !  

There's a solution for that.....

dont use it for pull  throughs!!!

(and use a replacable bit of kit for the bit that gets worn, like a mallion or ring and chain)

SamT said:

(and use a replacable bit of kit for the bit that gets worn, like a mallion or ring and chain)

Click to expand...

but if that bit of kit is also made of 316 you have the same problem of potential corrosion, though I accept it would be easier to replace.  May be one would have to settle for such a lesser satisfactory regime.

Bob Mehew said:

It is a problem for anchors in the sea cliffs above some caves which is why E&T and DCUC are searching for an alternative to 316 anchors.

Click to expand...

There must be tens of thousands, if not hundreds of thousands, of 316 (or worse) climbing bolts in sea cliffs around the UK and as far as I know no reported cases of SCC? I just don't think we have the climate for it.

Chloride Stress Corrosion Cracking (ClSCC) requires three precursors to be present, chloride ion, stress and temperature.  Clearly beside the sea, chloride ion concentrations are going to be high and above the threshold.  Stress is something we no real handle on so one can only be prudent and assume that it is present and sufficient to be above the threshold.  (Though where one has a weld, then unless the manufacturer has stress relieved the product, then stress is almost certainly present.)  Temperature is the key and research indicates temperatures as low as 25C can cause ClSCC to occur.  Whilst the UK does not traditionally have many days where a sea cliff sees over 25C one cannot rule them out.  (Perhaps I should have made clear I am talking about anchors at the entrance to a cave, not down within the cave where temperatures are low.)  The rate of corrosion can be fast (I first came across it when a stressed steam generator failed with a 3m long crack in just 90 seconds).  So how many days would it take of hot weather?  So it comes down to temperature being the only defense, unless one goes to some other material.  See http://british-caving.org.uk/wiki3/lib/exe/fetch.php?media=equipment_techniques:chlscc_v2_130909.docx for detail.

I would expect that a steel fixture in a south-facing cliff, exposed to the sun on any day between April and September would regularly exceed 25 degrees simply by absorption of strong direct solar radiation, even with the ambient air temperature being lower than this.

Bob Mehew said:

I am not sure but I think both Petzl anchors are made from 316 Stainless Steel which if the placement is on a sea cliff (as seems to be the case from one photo), would not be a good location for 316 anchors, never mind 304 SS. 

Click to expand...

Just had a communication from Lyons on behalf of Petzl saying they were declared in 2007 as being made of 304.  If you want 316, then use the Couer, see https://www.petzl.com/NL/en/Sport/Anchors/COEUR-BOLT-STAINLESS#.V0MD7b5GhaQ or for HCR, see https://www.petzl.com/NL/en/Sport/Anchors/COEUR-BOLT-HCR#.V0MDv75GhaS .