Hexentric

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Hexentrics: Large and medium-sized with hollow profile, small with full profile, with wire loops and cord.
Hexentrics from Black Diamond

A Hexentric ( Greek hexa "six", colloquially "Hex") is a mobile, d. H. removable climbing protection that is anchored in cracks, crevices and openings in the rock. It is used as an intermediate backup or stand security . Black Diamond calls the clamping wedges Hexentric, Wild Country calls them Rockcentrics.

Construction and shape

The Hexentric is shaped as an asymmetrical hexagonal profile, which is beveled on the front sides. Typical sizes vary from about 10 to 100 mm. Smaller Hexentrics, i.e. H. below a diameter of approx. 20 mm, are mostly designed as a full profile, while larger Hexentrics have a hollow profile in order to save weight. On two parallel, opposite long sides there is a pair of holes through which a closed wire loop or cord is passed.

The three other pairs of sides are each slightly beveled against each other so that they taper towards the long end of the wire loop. The distances between these three pairs of sides are staggered, so that a Hexentric provides the user with three different wedge sizes. The sides are planar at Hexentrics, while at Rockcentrics they are curved. In the latter case, a convex and a concave side are usually opposite one another.

A nominal fall load is indicated in the form of an imprint. This is mostly above 10  kN .

Operation and use

Hexentrics are mainly used in alpine or sport climbing . In doing so, they are clamped into existing structures in the rock, which run in the main load direction.

The main direction of loading points downwards in the case of intermediate securing as the direction of fall, likewise in stand construction ; there, however, it can also point upwards if the Hexentric is used to brace the stance downwards. Lateral main directions of loading are also possible if the Hexentric is braced with other mobile securing material.

Structures that run forward are mostly found in cracks in the rock, between large boulders and at the openings of cavities. The Hexentric is inserted into the opening from a wider point and placed in such a way that two opposite sides, which are conical due to the design and thus form a wedge, are positively clamped in the opening. In this position, it is tightened to prevent it from accidentally slipping out.

The Hexentric can be placed in three possible orientations: clamped between the two different loop-free long side pairs and between the front sides. The wedge widths are different in all three possible orientations, so that an orientation can be selected that matches the rock structure.

After use, the Hexentric can be removed backwards. If it gets stuck, it often helps to pull or tear on the wire loop or cord against the main load direction. Wedge removers are also used to loosen stuck Hexentrics.

More information

Hexentrics mainly keeps tensile loads and falls in the intended main load direction. A load in another direction can tear the Hexentric out of its position. The explosive force transferred to the rock by the wedge effect is significantly higher than the tensile load. Therefore, the risk of failure of a Hexentric in the event of a fall is also linked to the strength of the rock.

In order to be able to cover a wide range of clamping widths, climbers usually carry several Hexentrics of various sizes and other clamping devices, e.g. B. wedges with it. Hexentrics are mainly used for large crack widths. They cover roughly the same clamping width range as Friends , but have two advantages over them: Particularly great robustness due to the lack of moving parts and the comparatively low price. Hexentrics are offered by numerous commercial manufacturers. Typical prices are around € 8 to € 20 per piece.

Because of their shape and their typical sound, which is created when several Hexentrics hit the climber's harness when moving, they are sometimes colloquially referred to in the scene as “cow bells”.

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