How To Buy a Carabiner

Cara­bin­ers are the most indis­pens­able tool in a climber’s arse­nal. Used to quick­ly and safe­ly con­nect com­po­nents of a dynam­ic or sta­t­ic sys­tem, the cara­bin­er is worth its weight in gold. Here is a run-down of the com­mon types, shapes, and uses of a cara­bin­er.

Cara­bin­er Shapes: Cara­bin­ers come in a vari­ety of shapes that dic­tate not only the name but also how you’ll use them.

Oval Cara­bin­ers: Pop­u­lar tools in climb­ing quiv­ers, oval cara­bin­ers are use­ful for aid climb­ing and make excel­lent top-rope anchors when used prop­er­ly. They offer the weak­est inher­ent strength due to the sym­met­ri­cal nature of the cara­bin­er, which puts equal pres­sure on both the spine and the gate when loaded. The sym­met­ri­cal nature also can make them hard­er to han­dle.

D or Offset‑D Cara­bin­ers: The strongest shape and the most pop­u­lar cara­bin­er on the mar­ket, D or Offset‑D Cara­bin­ers car­ry most of the load on their spines, mak­ing them use­ful in almost all sit­u­a­tions.

Pear-Shaped (HMS) Cara­bin­ers: Pear-shaped cara­bin­ers are often used for belay­ing. They usu­al­ly offer a large rope-bear­ing sur­face and func­tion well with mod­ern belay devices. They are also called HMS cara­bin­ers, an abbre­vi­a­tion of the Ger­man Halb­mas­t­wurf­sicherung, which means munter hitch belay, refer­ring to the fact that they are unique­ly suit­ed to belay­ing with a munter hitch. For this rea­son car­ry­ing at least one HMS cara­bin­er is a good idea in case you lose your belay device.


Locking Mechanisms

In sit­u­a­tions where cara­bin­er fail­ure would be cat­a­stroph­ic and quick-release is not required, a lock­ing cara­bin­er is pre­ferred. The pri­ma­ry use is at anchor points and for belay devices.

The sim­plest lock­ing mech­a­nism is the screw­gate, which requires the climber to man­u­al­ly lock and unlock the cara­bin­er. Many peo­ple pre­fer this method because it forces them to dou­ble-check their main anchor points, and due to its sim­plic­i­ty it is reli­ably secure even in icy con­di­tions. Auto­mat­ic lock­ing cara­bin­ers will lock auto­mat­i­cal­ly, and are pre­ferred by aid climbers for their speed and in sit­u­a­tions when the rope will not be involved, such as clip­ping to an ascen­der or a Gri-Gri, but grit, sand, and ice may inter­fere with their oper­a­tion. The newest lock­ing sys­tem is a mag­net­ic lock, which seems to have the ben­e­fit of auto­mat­ic lock­ing with none of the draw­backs.

Gate Types: Cara­bin­ers are avail­able in stan­dard gates as well as wire gates.

Wire Gates: While stan­dard gates remain the go-to out of design neces­si­ty for all lock­ing cara­bin­ers, many peo­ple have moved to wire gates for most uses in sport, ice, and trad climb­ing. Wire gates offer the advan­tage of being lighter, poten­tial­ly safer (reduced gate flut­ter), and clear ice, snow, mud, and sand more eas­i­ly. They are as strong or stronger than stan­dard gates.

Stan­dard Gates: Some peo­ple pre­fer stan­dard gates in sport cara­bin­ers where a bend in the gate can make clip­ping eas­i­er (although some wire gates come bent as well).

Notch­less Gates: Notch­less have become more pop­u­lar as they are much eas­i­er to use and don’t get hooked up on bolt hang­ers, wired nuts, or slings when unclip­ping. Many man­u­fac­tur­ers now have designed notch­less wire gates, which offer the best of both.


Weight: Nowa­days cara­bin­ers are extreme­ly light­weight. The race to mak­ing the light­est has got­ten them down below 23 grams. Every ounce counts when you’re rock climb­ing, and if you have a big rack, buy­ing lighter cara­bin­ers can save you pounds. How­ev­er, you always have to con­sid­er usability—if your hands are too big to oper­ate the cara­bin­er eas­i­ly, or if you will be climb­ing in the win­ter, reg­u­lar-size cara­bin­ers are bet­ter.

Strength Rat­ings: All cara­bin­ers are rat­ed on their spine for three strengths: along the major axis, gate closed; along the major axis, gate open; and along the minor axis. This strength is mea­sured in kilo­new­tons, or kN. A sin­gle kN is about 224.8 foot-pounds of force, so a 25kN cara­bin­er is quite strong, capa­ble of hold­ing more than 2 tons of force—that’s more than two griz­zly bears. All cara­bin­ers are suf­fi­cient­ly strong along their major axis when closed for even the worst falls under nor­mal cir­cum­stances. How­ev­er, if the gate opens due to flut­ter or being pushed against the rock, the cara­bin­er’s over­all strength will sig­nif­i­cant­ly dimin­ish. An 8Kn rat­ing for open-gate strength is good, 10kN or bet­ter is ide­al.

Pro Tip: Nev­er cross-load your cara­bin­er along the minor axis, as even nor­mal falls can break them.