Snap hook

A snap hook is a metal ring having an easy system of opening. One can slip a cord, a ring there or make use of it as not of fastener. It is a connector used in particular in activities asking for the use of a Baudrier: Alpinism, Climbing, Speleology, Via ferrata, work in height (protection against the falls)… Within the framework of the nautical activities, one finds snap hooks on the veils, the Drisse S like on the safety straps.

There exist various types of snap hooks divided into two main categories:

the simple snap hooks, which do not have devices blocking the opening of the finger;
the snap hooks of safety, which have a system of locking to avoid the inopportune opening of the finger;

the automatic snap hook: it is equipped with a ring of safety relocating along the finger. Its use is proscribed in climbing but is authorized in Via-Ferrata,
the semi-automatic snap hook: the ring of safety requires a light rotation to be unbolted (a half-turn),
the screw snap hook: the ring of safety must be entirely unscrewed to be unbolted.

The shapes of snap hooks

Certain snap hooks more resistant than others and are adapted to the sports activities where the falls are possible even current, like the climbing.

the snap hook with broad opening of the type K (for Kleittersteige , via ferrata): this snap hook has a particular form enabling him to increase its space of opening, which facilitates its use in certain situations, in particular mousquetonnage on large cables or bars, and automatic locking. It is sometimes provided with a mechanics of locking per latch;
the snap hook of Spéléologie is traditionally oval and symmetrical, which facilitates its use with the specific material of descent and increase on fixed cord;
the ovoid “pear”, broad and not very angular snap hooks, are adapted to the use of specific nodes like the half-capstan.
the “fingers wire” offer as much resistance very but make it possible to reduce the snap hook while decreasing the probability of opening of the finger if the cord passes in the bad direction.

Resistance

According to the standard THIS relative to this category of EAR (IN 12275), the strength of the snap hooks breaking must be specified above (with marking THIS and the year of manufacture), according to three values: resistance in the main roads closed finger, resistance in the main roads opened finger, and, for the snap hooks of safety, resistance in the small axis.

For a simple snap hook, resistance in the main roads closed finger is approximately 2200 to 2500 Kilogram S, and from 700 to 1000 kilograms open finger.

For a snap hook of safety, resistance in the main roads closed finger is approximately 2500 to 3000 kilograms, from 700 to 1000 kilograms finger open and from 800 to 1100 kilograms in the small axis.

See too

External bonds

Snap hooks and connectors

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