Karabiners are the most important bit of climbing metalwork you’ll ever purchase. They are the clips that stand between you and a fall; they are the connecting links in your protection chain. They have multiple uses and there are a number of types, so for the uninitiated it can be confusing. So here’s a brief run through of what’s what in the world of karabiners.
Two main types of karabiner
As the name suggests, these don’t have a locking mechanism on the gate. This means that the gate is kept closed by a spring, so that ropes, slings or gear can quickly and easily be clipped into and out of it. Snapgates are normally used for runners or for racking gear; anywhere that speed and ease of clipping/unclipping is more imperative than security. Care must be taken to orientate the gate of a non locking karabiner away from the rockface, any ropes or objects that may push the gate open when in use.
There are 2 types of snapgate available.
Bargate – these have a solid metal gate, usually of the same diameter as the main body of the biner. These are available with either a straight gate or a bent gate. Bent gates have a slight inward curve, which makes clipping ropes faster and easier. They are also less likely to be accidentally opened in use. Straight gates as the name suggests have a straight bar across the gate. These are the most common type of snapgates.
A ‘Quickdraw’ using two snapgates will typically have one bent gate, which is used for clipping the rope into, and one straight gate, which is clipped into to the anchor point.
Wiregate – these are largely replacing classic snapgates as they have a number of benefits over them. They don’t freeze up in winter conditions and they don’t suffer from ‘gate flutter’ like snapgates can. Gate flutter can occur in the event of a fall; where the gate will basically will bounce open when shock loaded. They can be made lighter and stronger than snapgates, despite their flimsy appearance.
Locking karabiners (Screwgates and Autolocks)
These use the same basic design as snapgate biners, the main difference being that the gate can be secured or ‘locked’ shut. Locking karabiners are essential in situations where security and safety are paramount, such as clipping in to a system, rigging a belay or on abseils. If in doubt use a ‘locker’!
The most common form of locking biner is a screwgate. This usually consists of a knurled sleeve on a threaded bar. This can be twisted up to lock the gate or down to release it. One of the big drawbacks of the classic screwgate design is that they can be accidentally left unlocked or even become unlocked if the sleeve is pushed round or rolled when in use.
There are a number of autolock mechanisms that are available now which overcome this problem. These autolock’s can increase safety margins as they will lock automatically and cannot be accidently left open, but they are usually heavier and bulkier than regular screwgates.
Screwgates if over tightened can also lock closed. This is usually an inconvenience rather than a safety issue, but can be dangerous if you need to escape a rope system in an emergency.
Shapes of karabiner
Karabiners come in a variety of shapes and sizes. Modern technology has meant that karabiners can now be made in any variety of different shapes without compromising their strength, but as a rule karabiners will fall into one of these 4 basic shapes.
Oval – the oldest, most basic design of karabiner and not that common anymore. Cheap and easy to produce because of their regular shape, they can be used for all applications. The regular shape of an oval krab means it can be easily repositioned, even when loaded, making it a popular shape for aid climbers. The biggest drawback is that the load is equally shared with the gate side, the weakest part of the karabiner, so they aren’t the strongest of karabiner designs.
D shaped – This addresses the major drawback of the Oval design as it distributes the loading towards the spine of the karabiner, the strongest part, and away from the weaker gate. This shape is more complex to produce therefore these are more expensive biners.
Offset D – this is a tweaked variation on the D shape. It is a more teardrop in shape, allowing for more internal space where the gate opens. This makes clipping ropes and slings easier .
HMS or Pear shaped – these are the largest and usually the heaviest shape of karabiner and are shaped like a teardrop or a rounded triangle. They are almost always a locking karabiner. Similar to the offset D shape, they allow ropes and slings to be easily clipped, but due to their larger size they can accommodate bulky knots or several ropes at the same time. They are also shaped to be used with an Italian or Munter hitch belay.
Most modern sports karabiners are made using aluminium alloy (7075 Alloy). They are usually made by a process called hot forging; where a solid bar of metal is hammered into a mould (or die) whilst white hot from the furnace. This produces the strongest, lightest karabiners and allows more elaborate shapes to be manufactured.
To reduce weight further without, sacrificing any strength, many karabiner makers have incorporated ‘I beam’ construction into their top end biners. This means that high strengths can be achieved with less metal, thus meaning less weight. However I beam karabiners are expensive to produce, so expect to pay a premium for an ‘I beam krab.’
The word comes from "Karabinerhaken", meaning "hook for a carbine" in German.
HMS is an abbreviation for the German term Halbmastwurfsicherung