Should We Stop using Stainless Steel Bolts in Favour of Titanium Bolts?

Sheffield’s Titanium bolt guru, Martin Roberts, thinks Stainless Steel bolts should become a thing of the past; not just in super corrosive tropical environments like Thailand, but also in the UK.  Sarah Stirling finds out more.

When Martin decided to develop new sport climbing routes in Thailand a few years ago, he ran into a problem: Thailand’s environment is so corrosive the bolts had to be Titanium, but this light, strong and corrosive-resistant metal was incredibly expensive compared to traditional Stainless Steel.
Undeterred, Martin read a lot of books about manufacturing, spoke to a range of experts, designed a lot of bolts, out-sourced production to China and, finally, set up his own thriving business manufacturing Titanium bolts in Sheffield last year.

Aren’t Titanium bolts mostly useful in tropical coastal climbing areas, because these conditions accelerate corrosion?

It’s true that conditions are particularly bad in tropical coastal environments. Some routes in Thailand have been re-bolted with Stainless Steel five times in 20 years because the bolts have corroded so quickly. Climbers have occasionally broken both belay bolts at the same time in Thailand with just their body weight. Stainless Steel bolts don’t only fail on limestone in tropical coastal areas though. They have catastrophically failed in Basalt on Hawaii, in sandstone in South Africa 80km from the sea, and on Cuban crags more than 25km inland, amongst many other places.

OK Titanium is lighter, stronger and more corrosion resistant than Stainless Steel. But surely Stainless bolts work fine in the UK’s benign environment. Why do you recommend using Titanium bolts here?

I don’t think Stainless Steel is the best material for bolts. It certainly has a very limited lifespan compared to Titanium, and Titanium bolts are now no longer ridiculously expensive, so it makes sense to use them instead. The Titanium I use is not stronger than Stainless Steel by the way: I use it because of its superior corrosion resistance. Good quality Stainless Steel bolts (316 or A4) should be fine for inland use but for coastal environments, I would recommend Titanium.

But isn’t our rock and environment pretty benign in terms of causing corrosion?

In very general terms, corrosion happens faster in hotter climates. However, the corrosion of metals is an extremely complex process, affected by many different factors including proximity to the sea, porosity, composition and dampness of the rock, ambient temperature, humidity, rainwater run off, and rotting vegetation within and on top of the crag. I think Titanium bolts would be particularly useful in UK coastal areas because of the salt spray environment.

Why is Thailand’s climate particularly corrosive?

Thailand has all the corrosive characteristics: proximity to the sea, karst limestone, and rotten vegetation on top of the crag, which rots and seeps through the sometimes-porous rock. There’s also acid rain, which dissolves the limestone and deposits all sorts of nasty compounds on the bolts, such as magnesium chloride and calcium chloride. The high ambient temperature is also a problem, and there’s high humidity and also low humidity to contend with, so the damp compounds are concentrated when the water evaporates. There are also lots of people climbing there and therefore lots of falls on the bolts.

How did you go about designing your own Titanium bolts? 

I asked the designers of the original Ushba bolt if they minded me putting their bolt back in to production. The Ushba bolt had been unavailable for about 10 years because the company that produced them was bought out, then the price of bolts doubled so sales plummeted.

The first certified Titanium climbing bolt on the planet and designed to last generations even in the harshest climbing environments! Designed to fit in a 14mm hole and the strong spring interference fit ensures they will not slide out when placed in to any angle of rock while the resin cures.

Breaking load 45kN. Every bolt proof loaded to 8kN.
Proudly made in Sheffield, the heart of UK manufacturing excellence.

Leg Length GBP USD Euro
80mm £8.00 $12.40 €9.20
100mm £8.50 $13.18 €9.78
120mm £9.50 $14.73 €10.93


Why the Ushba bolt?

It was a simple proven design and, up until then, the only Titanium bolt used for climbing. Back then I didn’t have the time or resources to produce a new design and we were desperately in need of a bolt to cure the increasingly dangerous situation. The Ushba designers were happy for me to start producing the bolt again.

How did you go about getting your bolt designs manufactured?

I made some minor improvements to the Ushba design and emailed drawings to a few companies specialising in the manufacture of small Titanium parts. One of the companies that produced samples for me immediately became my preferred supplier. Mechanical testing carried out in Sheffield confirmed that, not only did their bolts look great, they were manufactured to very tight tolerances – ie the finished bolts were extremely similar, which indicated very good consistency in their manufacturing methods.

Did you start selling your bolts straight away?

No, in those days I had the bolts made on a non-profit basis for myself and my friends. We set about bolting new routes and re-bolting existing routes with them: mostly in Thailand, Hawaii, the Cayman Islands and also a few crags in Brazil.

Did you have any previous experience or qualifications in manufacturing, or did you learn as you went along?

I’ve always loved repairing and manufacturing things but had not previously studied Titanium manufacture. I was fortunate to bump into the right people at the right time and glean a huge amount of knowledge from experts in metallurgy, machining, coatings, corrosion, mechanical testing, failure analysis, welding and more. I also spent a huge amount of time reading papers, online documents, and manufacturing literature.

You’ve done accelerated corrosion tests on your bolts, and said that there’s no known case of a correctly placed Titanium bolt failing. What other tests have you had done on the bolts and do you have figures?

In those corrosion tests, a Stainless Steel hanger failed after less than 4.5 hours and the Titanium bolt was untouched after the full 30 days of the test. There is a huge amount of testing carried out on our products. The new Eterna bolts and U bolts we sell are certified to EN959 (the test all climbing bolts and anchors should pass – basically it’s to do with the dimensions and mechanical properties) and break at over 40kN – the minimum requirement is 25kN. A few other things we do: test every bar to make sure it’s true to its material certificate, dye penetrant tests to inspect for cracks, 100% visual inspection at various stages, and potassium ferrocyanide tests for surface iron after passivation.

Titanium is harder to get hold of, harder to machine and more expensive. Do you think UK climbers are going to fork out for the more expensive Titanium when, as you said, Stainless Steel works fine in a lot of places?

Stainless Steels should last OK in inland areas but will last nowhere near as long as Titanium. It’s not necessarily harder to machine but it is different and, yes, Titanium raw materials are more expensive than Steels. However, because we sell directly to customers and our overheads are lower than very large companies, we can sell our Titanium bolts cheaper than some Stainless Steel bolts. Even if you compare our Titanium bolts to the very cheapest steel bolts, Titanium will be the most economical option in the long run as they will last many times longer.

Can you tell me a bit more about the Thaitanium Project you’re involved with?

I’ve been supplying the Thaitanium Project with bolts for the last 4 or 5 years. It’s a non-profit effort dedicated to providing and installing Titanium climbing bolts throughout the Railay peninsular in Thailand. This winter I placed 500 bolts in Thailand as part a long-term corrosion test in association with the UIAA (International Mountaineering and Climbing Federation). The goal is to compare the corrosion and failure rates of four different grades of Stainless Steel in five different designs and our Titanium bolts; some expansion bolts and some glued in with four different types of resin.

What made you decide to bring manufacturing back to Sheffield?

I’d been manufacturing Titanium bolts in China for four years, and wasn’t advertising anywhere, but people were somehow finding me and asking for bolts. It seemed there was easily enough demand to start my own production and get the bolts certified. Manufacturing in the UK would allow me to oversee every aspect of production. By that time I had already made a lot of contacts in the manufacturing, metallurgy, titanium stock-holding and mechanical testing industries in Sheffield and it seemed an obvious decision given the city’s manufacturing heritage and it also being my home city.

How is that going – what pros and cons have you found to UK manufacturing?

Since starting the company in June 2013, we’ve gone from strength to strength: batches have got larger and sales faster. Dealing with China was always difficult with the distance, language and cultural differences. Now it’s easy and efficient. We drive a few minutes to purchase raw materials, tools and parts, or carry out mechanical testing. Die makers, passivation and welders with 30+ years experience with Titanium are also a short drive away. Almost everybody I’ve met through Sheffield manufacturing is a salt-of-the-earth type: honest, reliable and supremely helpful.

Any downsides?

The only downside is that labour intensive processes are costly here, so I’ve had to change designs to suit faster, more mechanised processes and make sure batches are large enough for the economy of scale to work in our favour.

So what’s next for Titan Climbing?

We are currently developing two new Titanium lower-off designs that will have a comparable price to Stainless Steel and will, of course last an extremely long time, have no moving parts to seize up and be very easy and safe to use.

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5 Responses to Should We Stop using Stainless Steel Bolts in Favour of Titanium Bolts?

  1. Greg Hart Jun 20, 2014 at 5:55 pm #

    Awesome that they are ‘affordable’ costing about the same as Stainless steel. Something to think about for sure

  2. Andy Davies Jun 23, 2014 at 8:17 am #

    The prices above would in reality equal a cost price in SA of >R190 per bolt
    Stainless Steel 316 corrodes at a rate of 0.1 micron per 10 years [CSIR study]. Assuming a corrosion allowance of 0.1mm, a stainless steel anchor would last 10,000 years
    All our failures in South Africa have been due to locally made anchors using bad steel. In my opinion, the lesson learnt is stick with the suppliers who make millions of anchors and who consequently spend lotsa effort on research and have very good Quality Assurance systems.

  3. Warren Gans Jun 23, 2014 at 3:58 pm #

    Um, Any I’m no physicist, but I didn’t realize 0.1mm of stainless steel would hold a 20kn fall. Secondly, that stat depends on where that bolt is placed in the country.

    I still think we need a more longer term view than thinking 10-30 years of life out of a bolt is sufficient: from the rocks perspective that is nothing.One day we will be looked at as the generation of climbers that added rust pimples to beautiful rock faces.

    The article above says the Ti bolts tested lasted 160 times longer than the SS (4.5 hours vs 30 days). This means we could be getting centuries out of a Ti bolt. Even if Ti only lasts 100 years, that is 4-7 times longer than an SS bolt, so that R190 vs R80 for an SS is actually cheaper in the long run and less effort in maintenance.

  4. Andy Davies Jun 24, 2014 at 7:48 am #

    Warren a corrosion allowance is the amount of corrosion you allow for in design. So for a 10mm diameter anchor, a corrosion allowance of 0.1mm would result in 9.8mm diameter anchor. For example,the Raumer 8mm diameter ANTRAX anchor can hold 22kN. So we can be assured a 0.1mm corrosion allowance is conservative. I’d say a design life of 10,000yrs is sufficient. Lets rather use that money to plant some carbon absorbing trees 🙂

  5. Warren Gans Jun 24, 2014 at 10:20 am #

    As I say I am ignorant, however I would bet that the SS bolts are placing now will be replaced within the next 35 years in crags like Kalk Bay and Kleinmond- one only needs to look at other bolts to come to this conclusion. I still dispute your maths above, because it would fail far before it rusted through.

    Thailand has a far more bolt eating environment than we do, but they are showing the worst case scenario as well as the practical differences between Ti and SS. It seems to be far more economic over the long term to use Ti.

    I don’t believe in stuffing up rock because we want to save a little money.

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