Friction hitch knots

On many rappels, a loop of cord wrapped around the rope acts as a third hand: it slides freely while all goes well and locks on its own if the brake hand fails. That small self-locking knot belongs to a whole family of friction hitch knots, from the Prusik of the Austrian mountaineers to the Blake's hitch of tree pruners, by way of the hitch that tightens the guy line on your tent. Here is why they hold and where each one fits.

🔒What is a friction hitch and why does it lock?

A self-locking knot is a knot that locks by itself. That is how the 2026 Height Rescue handbook of the Espírito Santo Military Fire Department (CBMES), in Brazil, defines the knots that tighten when pulled, such as the Prusik and the Machard. In English, climbers call this family friction hitches.

The secret is friction. With weight on the loop, the wraps close down on the main rope and bend it slightly, Wikipedia explains, and each extra wrap increases the grip. Petzl, the French climbing equipment maker, advises choosing the diameter and type of cord to suit the rope and adjusting the grip through the number of wraps.

One warning applies to the whole family: a hand gripping the knot undoes the friction. Animated Knots warns that holding the wraps of a Klemheist under load makes the knot slip and heat up.

In the club, the Prusik appears in four honors in the site's catalog: Knots and Lashings, advanced Knots and Lashings, Climbing and Rappelling. The Rappelling honor asks you to be able to use the prusik on a 10-meter cliff, and that only happens with an instructor.

🗂️What are the types of friction hitch knots?

Friction hitch knots fall into three families. In the first, a loop of cord, a lanyard or the end of the rope itself wraps the main rope for climbing or as a backup; only this family goes into systems that hold people, always under an instructor. In the second, the rope grips a pole or another rope pulled lengthwise. In the third, the rope grips itself to tension tarps and guy lines.

Difficulty: Desbravai knots and lashings catalog (October 2026). Uses: Animated Knots, Wikipedia and the CBMES handbook (2026).

🏔️What is a Prusik knot used for?

The Prusik Knot is used to climb a fixed rope and to back up someone who is descending. It is named after Karl Prusik, an Austrian mountaineer, and a mountaineering manual published in Austria in 1931 already showed it as a way to climb the rope, Wikipedia records. The Ashley Book of Knots has an identical design, number 1763, Animated Knots notes.

Its hallmark is symmetry: Petzl describes it as a hitch that locks in both directions. On the way up, mountaineers alternate two prusiks, a short one attached to the harness and a long one that reaches the foot (Animated Knots). The CBMES handbook also calls it prússico, its Portuguese name, and considers it the best choice for rescue, as long as it has the standard three wraps.

According to the CBMES, a three-wrap prusik slips at between 8 and 12 kN, roughly 815 to 1,225 kilograms-force. Wikipedia explains the advantage: when overloaded, it slips before damaging the rope and, in the extreme, the cord is what breaks from the heat. The price comes afterward, with the knot cinched tight and hard to untie; on wet, frozen rope, it stops doing its job.

The Purcell Prusik takes the idea further: a second prusik, tied on the loop itself, forms a loop of adjustable length. Popular with cavers and rescue teams, according to Wikipedia, it usually uses 6 or 7 mm cord (Animated Knots) and is gear for people trained in vertical rescue.

🔀Prusik vs Klemheist vs Machard: what is the difference?

The difference between the Prusik, the Klemheist and the Machard lies in the direction each one holds. The Prusik locks both ways. The Klemheist Knot is one-directional: after the wraps, one end of the loop passes through the other, and it only holds with the load in the direction it was tied. Wikipedia points out the advantage of accepting flat webbing, but notes that webbing slips under heavy loads and is not recommended for holding a person.

With the Machard, the names get tangled. According to the French Alpine Club in Marseille, Serge Machard, a 16-year-old climber from Marseille, created the knot in 1961, and the authentic Machard passes the carabiner through both loops of the cord ring, the design Wikipedia calls the autoblock. The same encyclopedia calls the Klemheist the French Machard; the South American Division's advanced Knots and Lashings honor lists a loop hitch or Machard knot; the CBMES handbook asks for at least five wraps and says it holds half the strength of the cord. When in doubt, ask the instructor which design they teach.

In its autoblock form, the Machard knot works as the third hand on rappel: clipped to the harness with a carabiner, it slides while the hand pushes it and locks if the descent gets out of control, Wikipedia describes. Petzl rates the autoblock as easy to release and locking in both directions.

Also outside the catalog, the Bachmann hitch, named after Austrian climber Franz Bachmann (Wikipedia), runs its wraps through a carabiner; gripping that carabiner loosens the wraps and the knot slips quickly, Animated Knots warns.

🌳Blake's hitch and Distel hitch: why do arborists climb with them?

Blake's Hitch is tied with the tail of the arborist's own rope, with no cord loop; an arborist is the professional who prunes and climbs trees. According to Animated Knots, Heinz Prohaska described it in an Austrian guides' publication in 1981; in 1994, Jason Blake presented it in a letter to Arbor Age magazine, and his name stuck.

It does not roll along the rope and holds in one direction only, with the force on the rope below it; pulling on the knot itself loosens it and causes an unexpected descent, the same site warns. Under a critical load, the tail is left long, and Wikipedia records that it usually gets a stopper knot, such as the Figure 8 Knot.

The Distel Hitch starts from a Clove Hitch with extra wraps on top, which form the spiral that grips the rope. Tied with a lanyard that has an eye at each end, it holds in one direction only. Animated Knots recommends it for arborists because it is reasonably easy to tie and comfortable to use, with the 4-over-1 form to start.

In the club, both help you understand the professional's work. The rappelling and zip line rule applies here: without a credentialed instructor, the activity does not happen.

⚓Rolling hitch and Icicle hitch: which friction hitch grips a pole or another rope?

The Rolling Hitch ties a smaller rope to a larger one with an almost parallel pull. According to Animated Knots, the second turn, tucked inside the first, bends the main rope slightly and secures the grip; the pull has to follow the line of the rope, and on very slick material, such as Dyneema and polypropylene, it does not hold. The origin of the name is in the guide to sailor knots.

The Icicle Hitch (Loop Method) was developed by John Smith of the International Guild of Knot Tyers (IGKT) and demonstrated at the Guild's annual general meeting in 1990, according to Wikipedia. Like the icicle in its name, it copes with a taper: it holds even on a tapered piece, such as a sailor's marlinspike. In August 2009, Practical Sailor magazine rated it better than the rolling hitch, Animated Knots reports. The Icicle Hitch (End Method) is the same hitch tied by passing the end, for when the end of the pole is not free.

At camp, this family pulls a pioneering pole lengthwise; increase the force gradually and never use it to lift people.

⛺Is there a self-locking trucker's hitch to tighten a line?

Searches for an auto-lock trucker's hitch or a self-locking tension knot mix up two ideas. The Trucker's Hitch builds tension with a loop that works like a pulley, and the two half hitches of the finish are what hold that tension; Animated Knots notes that finishing with a rolling hitch makes adjustment easier. What Brazilian law says about rope on cargo is in the guide to knots for tying down cargo.

For a line that adjusts and locks by itself, the answer is the third family. The Midshipman's Hitch (number 1855 in the Ashley Book of Knots) is, according to Animated Knots, a rolling hitch tied on the standing part of the same rope. Wikipedia, which covers the three variants of this adjustable hitch in its taut-line hitch article, calls it the most secure of them, although harder to adjust after a heavy load.

The Adjustable Grip Hitch, the Farrimond Friction Hitch and the Adjustable Sling Knot follow the same principle: fine adjustment of guy lines, a quick release with one tug and setting the length of the guy line. Which one to use on each line is in the guide to knots for tightening a rope. None of these hitches holds a person, a hammock or a suspended load.

✅How do you test a friction hitch and which mistakes should you avoid?

Animated Knots recommends checking, before any use, that the hitch grips and releases well, and finding out close to the ground how many wraps work with those ropes. Petzl points out that these techniques require training with a professional.

In the club, practice happens on the ground, with a rope tied between two posts at waist height. Push the hitch to see if it slides, pull the loop with increasing force to see if it locks, ease off and release, until you can feel by touch that the wraps lie side by side, without crossing.

The most common mistakes are well known. Animated Knots warns that efficiency drops as the diameters get closer, and Wikipedia notes that cord that is too thin loses strength and cinches too tight. Dyneema has a very low melting point and is not suitable for a prusik, except in parts designed for it (Wikipedia). On rappel, the CBMES handbook warns about a friction hitch below the descender rigged too long, which can get pulled into the device and jam it.

Cord and rope come from a certified manufacturer. The European standard for accessory cord is EN 564, and the UIAA, the international climbing and mountaineering federation, published the third edition of UIAA 102 in July 2025, which adds requirements to EN 564:2023.