We often find 304 pretending to be 316, but now I uncover a case of 303 posing as 304. Yeah, yeah, I know, it was twenty years ago, and we do things better now. But, if we don’t understand how such things happened, how can we be sure they won’t happen again? I suspect this […]
Preliminary report on the St Savvas anchor, which failed with lethal consequences on 27th March 2026 I would like to extend my condolences to all those who were touched by this terrible event. It is my earnest intent, through the pages of Crag Chemistry, to shine a light on such wild and unexpected failures as […]
time and again, we find that the nickel content of failed 316 is below specification, until… Thanks to Josh Lyons of the Thaitanium Project for the heap of corroded hardware pulled from the walls of Railay/Tonsai. Without such real world samples, all is mere speculation. We find a broken bolt from Railay/Tonsai which is absolutely […]
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Thailand Crags – 2
Sulphide Stress Cracking (SSC) The second part of a multi-part series For SCC see Part 1 Tonsai/Railay is where stainless-steel anchors go to die. We can now add, that the cause is SRB-mediated SSC. Introduction: I owe much to Martin Roberts of Titan Climbing for taking the initial steps of our great adventure into crag chemistry. […]
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Vale Luis Fernandes Silva
It is with great sadness that I must inform my readers of the passing of Luis Fernandes Silva following a work accident on the 8th July 2025. I will sorely miss, but never forget, this thoroughly decent person, and the contribution he made to my bolt corrosion investigations. May I extend my condolences to family […]
Is there a problem with severe bolt corrosion on Kalymnos… yeah?… nah? Let’s review what we know. Many thanks to Jorge Jordan for sending me the broken bolt, and thanks also to Emanuele Pellizzari for the wall-wash samples. Introduction: In September of last year, Facebook lit up with a report of a bolt failure at […]
The peculiarly aggressive corrosion of climbing anchors on certain sea cliffs can be attributed to sulphate reducing bacteria (SRB), but what of the distinction we see between 304 and 316 grades of steel? Introduction: Many years ago, when the crags of Tonsai/Railay began eating 304 stainless steel anchors it was felt that swapping over to […]
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Thailand Crags – 1
Chasing Some Demons The first Part of a multi-Part Series Introduction: Tonsai/Railay is where stainless-steel anchors go to die. So, this is where it all began. Actually, I tell a lie, it began elsewhere, but, as far as notoriety within the climbing community is concerned, our story begins many years ago on the tropical beaches […]
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Is this a 316 failure?
Hmm! it appears we have A4 (316) SS failing on a sulphate crag? It’s time to measure stuff. Many thanks to Simon Alden for the sample and photographs. This story comes from the sea cliffs of Malta. Whilst I don’t have significant geochemical sampling for Malta, I have every reason to believe the Mediterranean location […]
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The Face of Hydrogen Embrittlement
Occasionally we see evidence for the diffusional path of hydrogen. Many thanks to Luis Fernandes Silva for the photos and sample. I was skimming through some photos that Luis sent me a few years ago when one in particular, from Sesimbra del Drento, caught my eye. This crag is a high-sulphate, sea cliff where the […]