Big Nuts

November 8, 2008

Reading Time: 14 minutes.

Large homemade nuts had been around in the UK for many years, made from both large machine nuts, wooden blocks and even pipe, and in most articles about the history of the big nut it’s usually Tom Frost who’s given the honour of designing the first proper alloy hex, with the Chouinard Hexentric which appeared in 1971. In fact Clog in the UK where producing Hexagons as early as 1966, which seeing as clean climbing comes from the UK it seems pretty obvious that we’d beat the yanks to it. Never the less it was Chouinard’s Hexentric that really broke new ground as its sides were unsymmetrical, making it far more versatile than a plane hexagon, with its 6 faces offering the user at least 4 different possible placements of differing size (a hexagon could only offer 3). Added to this was the nuts low weight for its size and low cost, and it arrived in time to help the worldwide export of UK clean climbing ethics. The Hexentric was joined by several other large Hex-style nuts from companies like Troll and further improvements from Clog, but it was the Hexentric that most people had on their harnesses worldwide.

What all but killed the hex was the introduction of Friends and other camming devices in the late 70 and early 80s, which although heavier and far more expensive had the advantage of working in parallel cracks, along with much easier one-handed placement, and it looked like the hex would go the same way as wooden wedges for the majority of climbers.

Alpine and winter climbers, mountaineers and those who were too poor for cams carried on using Hexs, but the real turn around in the hex’s fortune came in the form of Wild Country’s Rockcentric, which took that 70’s design and gave it a 90’s design and material makeover and most importantly adding the curved face to the design. The result was an overnight classic that was so light and useful that climbers were again adding Hexs to their racks, and most importantly discovering that although they weren’t cams, cams were also not Hexs!


Firstly Hexs, and when I say Hexs I’m talking about nuts bigger than a Rock 10, give simple passive protection, working like any other nut. Unlike cams they won’t gum up with dirt or freeze, they don’t walk, and weight and cost only a fraction of an equivalent sized friend and are often stronger, and most importantly for abusive climbers, unlike a cam when they don’t quite fit you can hammer them in! So why use cams? Well, cams are generally faster to place and remove, requiring less thought, especially for beginners because although appearing simple Hexs do require a high level of skill in order to work effectively (even though Hexs were for a long time the badge of the novice). The most important difference is that cams work in parallel-sided cracks where Hexs are harder or impossible to place, and they will work in flared placements as all four cams can adjust to the shape of the placement, something the fixed-sized hex can’t.

But like most gear, it’s not an either-or question as Hexs and cams complement each other. This is especially true in the larger sizes, where you have very limited protection possibilities, for example, if you have only one Friend 2 and you use it in the first 20 feet then what do you do? If you also have a rack of Hexs then you should have at least two more pieces that can fit a 2-inch hex and a small hex placed sideways. Hexs also come into their own when setting up belays, as they are not only more reliable (shifting around shouldn’t cause them to walk) but they also allow you to save your cams for the sharp end. The weight difference of Hexs over cams comes in handy when you want larger sized protection but don’t want the weight of larger cams, perhaps if you’re climbing in winter, where cams may not work anyway, or on a rock type where cams aren’t essential, or just want to keep the weight as low as possible.


Hexs come in three very different styles, wired like standard-sized nuts, slung on Dyneema tape, or supplied loose so that you can decide what length or type of cord you want, the question is which one’s works best? As usual, the answer is that they all have pros and cons.



The stiffer cable can make it easier to place Hexs into spots that are out of reach on all but the largest sizes, making them preferably perhaps for routes where you don’t have to luxury of placing the hex by manipulating the nut itself with your fingers, such as on hard crack climbing where you want to place the hex as high as possible. Another advantage is that wired Hexs stay rack neater on your harness, and don’t catch on Velcro or other gear like worn Dyneema can. They are also very tough and more resistant the wear, and it’s easier to identify if the wire is wearing out, something harder to do with slung Hexs.


Wired Hex’s tend to be slightly heavier than Dyneema (around 40/50 grams), and on paper, they are slightly weaker when new – although perhaps this can be offset by the fact that steel wire may well retain its strength over a longer period. The drawback of a stiff wire is that it also requires extending, as the wires tend not to be very long or flexible to be used alone, meaning more extenders may need to be carried. It for this reason also that wired hex make worse improvised extenders, plus the fact that it’s impossible to tie knots in the cable make it harder to improve the hex’s effectiveness in some special circumstances.



First of all, Dyneema is God’s gift to climbing, being immensely strong, tough and very, very lightweight. It was by combining this type of sling with large nuts that made hex’s acceptable again as a great deal of weight was immediately slashed. The flexibility of the tape over cable and even rope makes the hex hard to jiggle free, saving extenders, plus their narrow diameter allows you to squeeze the tape through very narrow gaps – something impossible with old-school 11mm dynamic! Dyneema when new is resistant to freezing, and even when it looks tatty still retains amazing strength, as the fuzz usually comes from the nylon yarns that hold the sling together.


The soft Dyneema sling can make it hard to push the nut in if the placement is out of reach compared to a stiffer wire. Slings are easier to cut than wire, something that can happen in winter or alpine situations when axes are used to place and remove the hex, and they also don’t rack very neatly, especially when older and worn.



Having the ability to choose what length of tape or cord you want to use can be useful if you want to use the hex for very specific roles. Alpine climbers and mountaineers may want to place their hex on much longer slings so as to further reduce the chance of them coming adrift on a long run out pitches, plus give them a secondary role as near full-length slings. Many old school climbers complain that modern hexes are slung too short, pointing out that this is fashion over function, making loose Hexs perfect for those how still boycott calk. For those who are only interested in setting top ropes then hex slung on the longer static rope may also be of more use.


Wired and Dyneema slung Hexs are using the best technology available in order to gain the maximum advantage of the nut and set beside an old school hex sling on two metres of 9mm dynamic you can see why Hexs became as trendy as the Cheeky Girls.

People often ask if they can re-sling their large Hexs, generally removing the wire and replacing it with tape. This is easy to do, just cut the wire with a pair of wire cutters, and thread either 7mm cord or 5.5mm Dyneema or Gemini cord through the hole (most Hexs are designed to be re-slung this way), and for those who worry about such things - 7mm cord will give you a loop strength around 20kn.

Manufacturers won’t re-sling old Hexs as they would have to certify them safe, something they can’t do easily, meaning when the slings wear out you just buy a new one


It’s true that Dyneema slung Hexs are harder to place in out of reach spots, but with a simple little trick, it’s possible to gain a little extra reach. All you need to do is slide the tapes bar tacked section around until it’s pressed up hard against the nut itself. By pinching this stiff section with the softer section you can make the tape very stiff, perhaps helping you reach that sweet spot you couldn’t have reach otherwise.


The good thing about large Hexs is that they are easy to identify, especially if they are colour coded. One problem is that if you rack them all together you end up with considerable weight on one crab, with Dyneema and rope slung Hexs often tangling up. A good technique is to split the Hexs up, with the most useful sizes (20mm to 40cm) going on one crab that lives along with your wires, and the bigger sizes going at the back of your harness out of the way (but easily grabbed). If you find that you’re always reaching for that Hexentric 7 then consider placing it on a dedicated crab so you can just grab and place it. Having maybe three crucial sizes pre-clipped means they are also half ready to be used as quickdraws if you run out near the top of your mammoth lead. If you find that you’re big Hexs are always clanking around and doing you damage, then slide the nut to the middle and clip both ends together, so that nut only hangs half as far from your rack.


One great use for bigger heavier nut is as ballast when trying to keep crucial runners in their place, using them as weighted extenders. This is a very good technique when trying to keep slings on tiny spikes; although it’s at times like this that you’ll wish that the manufactures hadn’t done such a great job reducing the hex’s weight.