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What Is a Ball Nut?

LAST UPDATED: 4th January 2024

In trad climbing, there are many different tools we can use to get the job done. Most climbers, regardless of skill, will usually opt for some combination of cams and nuts when organizing their rack for a day on route. By and large, there are very few situations where a healthy collection of either will not suffice. There is, however, one tool that can be very useful, especially in dealing with small cracks where cams cannot go; The Ball Nut.

A Brief History

The Ball Nut was first introduced in 1987. It is not quite clear who exactly invented them, but as it stands, CAMP is one of the main manufacturers of Ball Nuts. While it is an effective piece of equipment, especially in smaller cracks, it came into the fold shortly after the invention of the SLCD (Spring Loaded Camming Device) by Ray Jardine in 1978, a device he first tested on The Phoenix in Yosemite. As a result, the Ball Nut is not often seen on a climber’s trad rack today. 

The reason for this is that cams, from all different manufacturers, have achieved a size and range to make Ball Nuts more or less obsolete. Still, just like the hexentric stopper or the tri-cam, Ball Nuts are well-suited to certain areas and types of terrain.

What Exactly is a Ball Nut?

The Ball Nut looks like some combination of a cam and a nut – there is a thumb loop, a stem and a trigger that activates the mechanism central to its function. As opposed to cams, however, the head of a Ball Nut looks similar to a thin stopper. This is called the paddle. The key difference between the Ball Nut and a cam is the mechanism which gives it the camming action needed to stay in a crack once it is set.

Ball nuts climbing equipment

How Does a Ball Nut Work?

When the trigger is pulled, a small flat-headed ball – fit into a central groove on the paddle – moves up and down with the depression or the release of the trigger. Just like a cam, pulling the trigger down will cause the ball to drop, allowing the head to be slotted into a crack. Once inside, releasing the trigger causes the ball to rise, slotting itself back into the paddle groove. This widens the profile of the piece, lodging it in the crack.

During a fall, the paddle still travels relative to the ball. What this means is that, naturally, there will be a little slippage of the paddle when a climber falls on this piece. Just like with other nuts and cams, there is a right and wrong way to place one. 

When a Ball Nut is placed, the bottom edge of the paddle should be even, more or less, with the bottom edge of the ball. Then, when slippage does occur during a fall, the ball will continue to slide up the groove until it has achieved a wide enough profile to arrest downward motion. Additionally, the ball is made of a softer metal alloy than the paddle. Therefore, when a leader takes a fall, the ball deforms to the rock, helping it to catch small ripples in the texture. For this reason, a Ball Nut is much better suited to a featured crack than a smooth one.

How To Place a Ball Nut

Placing a Ball Nut carries a little more nuance than placing a cam. Essentially, pull the trigger on the stem (as shown in the video above) and slip the nut into the crack. Release the trigger enough for the ball to slide into a good position, i.e. somewhere that it forces the paddle against the other side of the crack. Pull down to set it (this is a preliminary measure that will get some of the ball’s slippage out of the way early on), and you’re done!

Features of a Good Placement

When looking for a good Ball Nut placement, there are some cardinal rules that should be followed. Just like with any other piece of protection – Cams, stoppers, tri-cams, etc. – one of the most important aspects of a good placement is good rock. If the rock is rotten, an agitating force is likely to shave off the outer layer, causing a piece to fail. A Ball Nut is no exception in this regard; make sure that the ball, especially, is resting on solid rock. Good granite is one of the best applications for Ball Nuts.

ball nut placement
This is good placement for a ball nut

Just like with a cam or a nut, a slight constriction in a crack is what you are looking for. Perfectly parallel-sided cracks are not ideal. When a Ball Nut is placed under load, the paddle is what moves downward, not the ball. For this reason, it is a good idea for the ball to be resting on a ripple or edge that it can use for purchase. 

In a v-slot or taper feature, a normal stopper is still the preferred tool as – in this setting – a Ball Nut is liable to “walk” once the climber gets above it. For this reason, always extend your Ball Nuts to reduce the chances of “walking.”

Removing a Ball Nut

Taking a Ball Nut out of a crack should be similarly easy to removing a cam; simply pull down on the trigger, releasing the ball from the paddle grove and pull it out! On the other hand, if the paddle is too fixed against the crack by the ball, the best strategy is to try and push the paddle further into the crack. The ball should stay roughly where it is and allow the paddle to move freely. Once the two pieces are no longer relying on each other to stay in the crack, the piece will be easier to remove.

Ball Nut Vs. Cam

The long and short of it is that cams are superior to ball nuts in most ways; ease of placement, reliability of technology, etc. However, in smaller cracks where a cam lacks the expansion, and therefore the stopping power, that it wields in larger cracks, the Ball Nut is the obvious choice.

The strength of cams comes from the ability for its lobes to expand and, literally, to cam against the walls of a crack. On smaller cams, that range is less because the lobes only have so much surface area with which to cam. Ball Nuts, on the other hand, rely on the slippage of the ball into the paddle groove to create expansion. If properly placed, this slippage will create the desired effect of fixing the Ball Nut into the crack. In other words, the expansive power of the Ball Nut is more than that of small cams in thinner cracks.

Will You Try A Ball Nut?

Ball Nuts can be an extremely effective piece to have on your rack, especially on a long alpine outing where – on a single pitch – you could be connecting far-apart features and, as often as not, running out of usable gear. Usually, there will be at least a couple very thin cracks, and if you know how to place them, Ball Nuts will occasionally surpass even a small cam in security and strength. 

Still – if I’ve said it once, I’ve said it a thousand times – you must practice with the Ball Nut before using it as a piece on lead. Find a boulder with a crack that you can use to practice setting these pieces. They can be tricky and remarkably unintuitive.



Born and raised in Northern Vermont, Zak's parents were hardcore adventurers, and the appearance of a child in their lives did not slow them down much. Each summer, they would toss him and an assortment of gear in the truck and gun it for the American West. After his first year at college, Zak applied for a job in Yosemite National Park, and for the next decade, he worked seasonally in Yosemite and on the Sierra Eastside, doing whatever he could to be close to those mountains. Currently, Zak lives on the north shore of Lake Tahoe, piecing together a living as a climbing guide, bartender and writer.

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