Fixe PLX and Petzl HCR – Worth the hype?
For a number of years, decades even, the choice of material for fixed rock anchors (bolts) was pretty much limited to stainless steel grades 304 or 316.
With the development of climbing areas within highly corrosive environments, so to has been the development in both anchor technology and climber knowledge concerning corrosion and its various mechanisms as they apply to rock climbing anchors.
Stress Corrosion Cracking (SCC) and the alarming rapidity with which anchors are rendered dangerous has gripped the community on a global scale and driven the development of titanium resin bonded anchors as a direct result. The investigation of SCC in Southern Thailand has had an impact within the materials engineering world by raising awareness that SCC can occur outside of the conditions traditionally believed to be the required norms.
The well known efforts of the Thaitanium Project (http://thaitaniumproject.com) and Titan Climbing (http://titanclimbing.com) have led to a full range of titanium products that compliment the high quality stainless steel products from Bolt Products (http://bolt-products.com).
Climbers equipping new routes have the choice of an excellent range of stainless steel products for normal use and equally titanium where SCC / harsh corrosion is affecting hardware. With Fixe introducing their PLX range and Petzl with an ‘HCR’ product line, what are the benefits and are those products anything better?
- The Fixe PLX range is based on duplex stainless steel grade 2304, although may contain a blend of other duplex stainless steels.
- Duplex stainless steels have good resistance to SCC however remain affected by pitting and crevice corrosion, both types of corrosion that can act as initiator mechanisms whereby SCC develops at a later stage.
- Stainless steel grade 926 expansion bolt and a 904L grade stainless steel hanger
- 926 grade stainless steel should contain a minimum of 6% Molybdenum and generically is described as a high corrosion resistant steel.
UIAA studies underway intend to determine a range of materials as matched to a set of environmental conditions since simply stating something is corrosion resistant is meaningless without equally specifying the corrosion it is supposed to resist. The use of the term HCR is misleading in that regard.
Duplex steel has high resistance to SCC and high quality steels in the 6% Molybdenum range resist SCC so where does that leave climbers trying to ascertain the relevance of these new products against what already exists on the market? Two considerations foremost in mind is the cost of the fixing and known performance in real world climbing applications. Looking at pricing online with no discounts applied:
- 304 Grade Stainless Steel glue-in bolt (Bolt Products) – $5.00 (inc $1 for adhesive)
- 316 Grade Stainless Steel glue-in bolt (Bolt Products) – $5.21 (inc $1 for adhesive)
- Fixe PLX (MEC Online) – $11.60
- Titanium glue-in bolt (Titan Climbing) – $13.12 (inc $1.28 for adhesive)
- Petzl ‘HCR’ (Petzl Online) – $36.00
316 grade stainless steel is a cost effective option in areas not affected by SCC.
Fixe’s PLX hardware is roughly around the same price band of Titan Climbing’s titanium hardware but the Petzl ‘HCR’ is quoted at an astronomical US$ 36 (pack of 20 list price).
316 and Titanium already has proven use in a variety of regions with varying degrees of corrosion. Where SCC is occurring, a titanium bolt glued in with pure epoxy is currently considered the best form of fixed protection.
Fixe have just initiated a batch recall for their PLX bolts in response to severe corrosion affecting hangers. The reasons for this are not currently in the public domain but this does highlight the issue facing developers when new products are launched to either build in company liability where the product line was only 316 based or perhaps to counter titanium based products. Without a ‘track record’ developers take the risk in installing hardware only to find it won’t last some 5, 10 years or longer, later.
Technical materials knowledge within the oil and gas industry says 6% Moly’ steels will resists SCC however the UIAA is yet to issue a guideline to climbers to this effect. The fundamental issue facing the use of Petzl’s ‘HCR’ range however is cost and it is simply too expensive unless the unit price is reduced to become competitive with titanium glue-ins. The drawbacks associated with using bolt ins however are not eliminated.
Ultimately when the track record of certified titanium glue-in bolts is considered, the advantages this type of fixing offers, and the pricing for a known SCC resistant material, why switch to duplex 2304.