The carabiner is a metal ring equipped with a spring-loaded door, which can be quickly opened to disconnect the components of the safety device. The word ‘carabiner’ comes from German karabineerhaken, which means “snap hook carabiner of a carbine,” translated and abbreviated to English carabiner.
The carabiner can only be opened manually by pushing the door away from the ring.
The snap hook carabiner is very similar: a hook with a spring opening allows the rope or rope to enter the hook and loop, but do not leave it unless you pull a small knob down with your thumb to open the spring.
When purchasing snap hook carabiners or mountain buckles, you should ensure that their spine is engraved with a kn rating (kilonewton). If you do not have these ratings, please do not use them to protect yourself or others from falling!
A kilogram of Newton is about 225 pounds. This is the level of gravity, not the weight of the object. So if you weigh 150 pounds, your gravity equals your mass (150 pounds) times your acceleration.
The kn rating is designed to help you find snap hook carabiners or mountain buckles that can withstand the forces of a fall. In other words, when the body falls, the snap hook carabiner or carabiner will help prevent the body from falling entirely to the ground, as long as the kn rating is compatible with the impact force generated by the individual body.
All snap hook carabiners and mountain buckles are designed for people who weigh no more than 420 pounds.
The American National Standards Institute (ANSI) requires that all types of hardware designed to protect individuals from falling have a gate rating of at least 16 kn and a tensile load rating of 22.5 kn. These ratings are converted to 3600 and 5000 pounds, respectively. This standard came into effect in 2007, so if your snap hook carabiner or carabiner was manufactured before 2007, it is wise to replace it because the new standard provides 16.3x the required rating.
Remember that this rating does not consider any wear on the gears, so you must check all equipment and replace excessively worn snap hook carabiners and mountain buckles (and other safety equipment) before use. Stopping a fall will bring considerable pressure to the equipment. Once the tool completes (restraint/rescue) work correctly, it is wise to replace it.