Which Accessory Cord is Suitable for a Prusik Hitch?

The Prusik hitch is a friction knot wrapped around the main rope, often used in outdoor climbing. For example, during ascent along a main rope, the Prusik hitch can function as an ascender; during rappelling, it serves as a safety backup—if the descender fails, it can tightly "grip" the main rope.

So, how do you choose the right accessory cord to make a Prusik hitch?

When engaging in activities like rock climbing, glacier trekking, and rope ascending, the Prusik hitch is a crucial tool. However, different materials used for the hitch have their own advantages and disadvantages. Below, we explore three commonly used materials for Prusik hitches: nylon accessory cord, sewn Prusik loops (pre-formed hitches), and rectangular tubular sewn slings (fire-resistant webbing).

1. Nylon Accessory Cord

Choose a cord of appropriate length based on actual usage needs.

The key to selecting the right cord is that not all accessory cords are universally suitable. Generally, you need a cord with a diameter 3 mm different from the main rope’s diameter, but the cord diameter should not be less than 5.5–6 mm. This means the ideal diameter range for the accessory cord is 5.5–7 mm. Why? If a thinner cord is used on a thicker main rope, the hitch may grip too tightly, making it difficult to move. Conversely, a thicker cord may not grip effectively, requiring extra wraps.

A double-wrap Prusik hitch is typically used as a safety backup during rappelling. In other situations, a triple-wrap Prusik is used, though this depends on the interaction between the rope and the hitch.

Besides size, another important factor is the cord’s flexibility. You can test this by pinching a short section of the cord between your fingers. If the ends meet completely, it’s an excellent cord for a Prusik hitch. If a large gap forms at the bend, it won’t grip the main rope tightly, and you should consider a different cord.

The load-bearing strength of accessory cords varies significantly by manufacturer and diameter, but most 6–7 mm cords have a strength range of 7–10 kN. When doubled, they are sufficient for setting anchors and personal backup.

Pros: Wide range of options.
Cons: Lifespan, strength, and performance vary greatly among nylon cords. Some work well, while others don’t. Many gear shops sell cheaper cords that may not perform well for Prusik hitches, so it’s important to compare options.

Summary: If you can find a nylon cord with the right diameter and flexibility, it will perform exceptionally well for hitches. It’s also a great choice for making longer hitches (e.g., 5 meters). For less experienced climbers, purchasing from a local outdoor store is generally better than buying from large chain supermarkets.

2. Sewn Prusik Loops (Pre-Formed Hitches)

There are various sewn Prusik loops made from different materials, but here we focus on the most common ones available:

Brand: JIAOLONG

Core: Aramid fiber.

Sheath: Polyamide nylon.

Designed for hitches, with an abrasion-resistant sheath for durability and safety even in high temperatures.

Excellent knotting performance, easily grips thin ropes.

Sewn section protected with heat-shrink tubing. Lightweight and durable under repeated bending.

Lighter and more compact compared to mechanical ascenders.

Suitable as a hitch for added safety during rappelling or for hauling.

Recommended for Prusik or French Prusik hitches. Available in 6 mm diameter, 0.6 m and 1.2 m lengths.

Weight: 36 g. Sheath: nylon; core: heat-resistant aramid.

Loop strength: 22 kN. Can be used as a hitch or sling.

These loops, with an aramid core and nylon sheath, offer better heat resistance and longer lifespan compared to nylon-core cords. They are very soft, making them easy to handle even on thicker main ropes. A double-wrap Prusik works well as a safety backup on a single rope, while a triple-wrap may be necessary for double or twin ropes. They are also easy to untie after loading.

Due to their softness and smoothness, these loops work well with a wide range of rope diameters. Available in 0.6 m and 1.2 m lengths, both with a breaking strength of 22 kN. The 35 cm length is ideal for traditional Prusik hitches, while the 50 cm or 60 cm lengths are better for French Prusiks (Autoblock) or Klemheist hitches.

Editor’s Note: French Prusiks and Klemheists are common hitch types used for ascending and descending ropes during climbing.

If you’re choosing a sewn loop, for general climbing, the diameter should not exceed 7 mm. While 8 mm loops are available, they are primarily designed for 11 mm static ropes used in rescue or rope access work.

Pros: Durable, heat-resistant, very soft.
Cons: Can be difficult to find in stores.
Summary: An excellent choice for Prusik hitches and a popular option among many climbers!

3. Rectangular Tubular Sewn Slings (Fire-Resistant Webbing)

Brand: Haili Anxin
The "fire-resistant webbing" sling from Haili Anxin is a rectangular tubular sewn sling made entirely of aramid fiber. It is heat-resistant but has relatively average durability.

Available in two lengths: 0.6 m and 1.2 m, with a breaking load of 2200 daN (kg).

Heat-resistant and fireproof, compliant with EN566.

60 cm length, 10 mm width, 29 g weight.

120 cm length, 10 mm width, 53 g weight.

Material: Aramid.

While these rectangular slings can accommodate a relatively wide range of rope diameters, they are slightly less versatile compared to dedicated accessory cords. One drawback is that if the hitch is poorly wrapped, it may slip. This can be mitigated with careful use, but avoid letting the sling bunch up.

Pros: Soft, suitable for a wide range of rope diameters.
Cons: Prone to slipping or bunching if not properly handled.
Summary: When used correctly, it can serve as a reliable standalone Prusik hitch.

Overview

For personal use, some prefer soft materials that work well across a range of rope diameters. For multi-pitch climbing, carrying a 5-meter nylon accessory cord is advisable, with the key being to find a soft and smooth nylon cord.

Disclaimer: The above discussion on Prusik hitches does not make you an expert climber, and the author cannot predict how your gear will perform in all situations. For further questions, consult a qualified professional and follow product instructions.