KARABINER & QUICKDRAW

BUYING GUIDE

Man scrambling


Karabiners are essential elements of any climbing safety chain. Whether clipping protection, building a belay or simply belaying a partner, the karabiner always has a role to play. This buying guide explains the differences between the various shapes and sizes of karabiner available, discusses how they are made and also how they're tested so you can make an informed decision about which to buy for different types of climbing.

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Karabiner shapes

Karabiner Shapes

There are three main types of karabiner shape.

Oval

This uniform shape ensures that the load stays centred, thereby helping to avoid the dangers of cross loading. Oval screwgate karabiners are widely used on big wall and pulley set-ups. An oval wiregate is also great for racking nuts, allowing them to fan out evenly beneath the karabiner for easier selection.

'D' and Offset D

Adapted from the Oval shape, the original D has a straight back bar and symmetric curves to the gate. The focal point of the load is nearer to the back bar which increases the karabiner's strength slightly. Recently the D has been replaced as the versatile karabiner of choice by a non-symmetric variant, the 'offset' D. Like the standard D shape, this focuses the load along the back bar but a narrower lower section helps make the karabiner lighter. They can also generate a slightly larger gate opening. The angle of the upper curve is ideal for clipping through protection or bolts so this shape is the standard for quickdraws as well as general purpose use.

HMS

The HMS (short for the German “Halbmastwurf Sicherung”) is essentially a very large offset D. The extra size creates a wider and thicker top bar, which allows ropes to run very smoothly. For this reason many people will choose to belay with an HMS karabiner. The extra width and larger gate opening also allows for multiple ropes or knots (like the Munter hitch or two clove hitches) to be attached.

Karabiner Gates

Straight

Simple straight gates are the classic all round non-locking option. They are commonly used in quickdraws, especially for clipping protection or bolts.  Many solid gate karabiners now come with 'keylock' clean noses rather than a notched nose, helping to prevent irritating and potentially dangerous hang-ups where the gate and nose don't engage properly.

  Straight Gate
     

Bent

Bent gates give a slight advantage when clipping a rope; the rope is guided into the karabiner's basket by the curve of the gate. Bent gate karabiners are therefore often used on the lower end of quickdraws to facilitate quick clipping.  Like straight gates, many bent gate karabiners will have 'keylock' clean noses.

  Bent karabiner gate
     

Wire

Wire gates are a lightweight alternative. They use less metal but achieve the same strength ratings. They won't freeze up in winter, and they are more resistant to 'gate flutter'.
  Wire karabiner gate
     

Screwgate

Snap gates (straight, bent or wire) make sense for quickdraws where speed of clipping is crucial, but a locking karabiner adds security when belaying a partner or when building belay rigs. Screwgates are the most common form of locking gate and offer great value, but they do rely on the user to remember to do up the sheave every time. Keylock clean noses are increasingly common and help prevent snags.

  Screw Gate Karabiner
     

Twistlock

Automatic locking mechanisms like the Twistlock reduce the possibility that you might forget to lock your karabiner. However they can be trickier to open than screwgates (particularly one handed) and will usually cost slightly more.

  Twistlock gate karabiner
     

Magnetron

Black Diamond's Magnetron gate is essentially an automatic locking mechanism, but the two magnetic arms represent a very different (simpler) approach from double- or triple-action twistlock gates.

  Magnetron Karabiner Gate

Karabiner Uses

belaying karabiners

Belaying

When belaying it's important to use a karabiner with a generous top bar. Small, narrow-angled D shapes can exert too much friction on the rope and make belaying catchy and unpredictable. An HMS locking karabiner is ideal, though it's important to remember that screwgates must be locked manually every time. This explains why automatic locking HMS options are also popular. One of the other dangers when belaying is that the karabiner twists round and becomes cross-loaded across the gate. Specific belay karabiners that capture the belay loop can prevent this happening.

Belay building

Constructing safe belay positions at the end of a pitch is a skill in itself. Locking karabiners (usually offset D shape screwgates) should be used to connect slings or the rope to protection. You will then often need to bring together a few slings and/or bights of rope into one hub. This central point will often demand a large HMS locking karabiner. The key is to have several screwgate karabiners on your harness to deal with all eventualities.

Racking

Nuts, hexes, cams, slings and even approach shoes will often need to be attached to your harness. Simple snapgate (straight, bent or wire) karabiners are the best way to do this. An oval shape is great for racking nuts.


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Quickdraws

Quickdraws

Quickdraws are made up of two karabiners joined together by high strength webbing. When climbing, one karabiner is clipped to a point of protection, for instance a bolt hanger or camming device. This karabiner is usually able to move freely within the sewn sling to reduce the 'pull' on the protection. The other karabiner is clipped to the rope. This end is often secured within the sling by a tight rubber 'tadpole' which prevents the karabiner from twisting, thus reducing the possibility of cross-loading and keeping it well positioned for clipping the rope. The sling increases the distance between protection and rope (hence why they're often called 'extenders'). This allows the rope to run more freely with less risk of dislodging the protection.

For traditional climbs, quickdraws with lightweight wiregate karabiners are the norm. The wiregate is especially useful on winter climbs as it won't freeze shut. Thinner, lighter slings also help cut the weight of your rack on the harness. Carrying a variety of lengths from 10-12cm (short) through 15-18cm (medium) and up to 25cm (long) allows you to manage the line of the rope on meandering trad routes and when crossing roofs. A rack of a dozen quickdraws will usually suffice for most pitches.

For sport climbs, quickdraws with sturdy solid gate karabiners are the norm. Chunky karabiners put up with constant abuse and regular falls. Wider slings are much easier to hold when working routes and hauling back to your highpoint. A straight gate makes bolt clipping easy while a bent gate facilitates rope clipping. 10-12cm lengths are fine for most straight-up routes, but it's also worth carrying a few longer sport draws for occasional use. A rack of a dozen quickdraws will suffice for most pitches but long european sport routes might require far more. Guidebooks will often give the number of bolts for any route so you can check you have enough before setting off.

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DMM Karabiners being forged

Karabiner Manufacture

Climbing karabiners are generally made from aluminium (usually type 7075, an alloy also used in the aerospace industry).  This provides a fantastic balance of lightness, strength and hardness.

Forging

For decades karabiners have been built by 'cold forging', whereby aluminium rod stock is bent into the required shape at room temperature. The results are very strong and consistent. However they lack the finesse of modern hot forged karabiners. Hot forging requires the heating of both rod stock and dies. Hot metal can be moved around by the dies, allowing the creation of more complex and tailored designs. Metal can be concentrated where it's needed and removed where it's not needed. This process allows 'I-Beam' profiles as well as enhanced radii on rope-bearing surfaces and even clean noses on wiregate karabiners. Hot forging can provide lighter weight units with no strength compromise.

Anodising

Once the karabiner has been forged and heat treated, it can be anodised. Anodising thickens the natural oxide layer that covers aluminium alloys exposed to air. This process increases wear resistance and allows the durable application of colour.

The DMM video below takes you through much of the manufacture process of a Karabiner.

Strength Ratings

Statistics

Every climbing karabiner is required to display its strength ratings on the back bar. There are three statistics quoted; major axis, minor axis and gate open.

  • Major axis strength is measured for a load along the back bar with the gate closed (the normal mode).
  • Minor axis strength is measured for a load across the gate with the gate closed.
  • Gate open strength is measured for a load along the back bar with the gate open.

Karabiners are rated in kiloNewtons (kN), a measure of force. It's hard to visualise this dynamic measurement; if your karabiner is rated to 25kN along the major axis, what does that mean? A 25kN rating is roughly equivalent to a 2500kg mass under the influence of gravity. Therefore the karabiner would hold a static load of 2.5 metric tons.

Testing

Karabiners are tested on a pull rig which gradually ramps up the pressure until the karabiner breaks. The breaking force is recorded; the EN-12275 standard requires Basic and HMS karabiners to have major axis strength of 20kN and minor axis strength of 7kN. 

Go to 20:40 on the DMM video to watch a Karabiner being stress tested!

DMM and Black Diamond are two companies that use the 3 Sigma standard to establish their stated rating strength. Testing a large quantity of karabiners to breaking point, they derive a normally distributed bell-shaped curve. By quoting a breaking strain value that is 3 standard deviations (3 sigma) less than the actual average figure derived in testing, it is known that 99.87% of all karabiners produced will equal or exceed the stated breaking strain.

Buying karabiners and quickdraws

We hope this buying guide has helped explain the differences between different kinds of karabiner and what kinds of unit might be used for different types of climbing. To get a real feel for which models will suit you best it's always a good idea to hold them in-store, check how responsive the gate feels, whether it's the right size and shape and simply whether you'll enjoy clipping them on your next climb.

Feeling a bit more clued up? Shop our full range of karabiners and quickdraws here.