Carabiner Buying Guide

Introduction

Carabiners are necessary elements of any climbing safety chain. Whether clipping protection, building a belay or simply belaying a partner, the carabiner always has a role to play. Choosing the right type for each use is not just practical, but more importantly, it's also essential for your safety.

Carabiner shapes

Oval

'D' & Offset D

HMS

Carabiner gates

Straight

Bent

Wire

Screwgate

Twistlock

Carabiner uses

Belaying

When belaying it's important to use a carabiner with a generous top bar. Small, narrow-angled D shapes can exert too much friction on the rope, making belaying catchy and unpredictable. An HMS locking carabiner 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 carabiner twists round and becomes cross-loaded across the gate. Specific belay carabiners that capture the belay loop can prevent this from happening.

Belay building

Constructing safe belay positions at the end of a pitch is a skill in itself. Locking carabiners (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 carabiner. The key is to have several screwgate carabiners 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) carabiners are the best way to do this. An oval shape is great for racking nuts.

Quickdraws

What are quickdraws?

Quickdraws are made up of two carabiners joined together by high-strength webbing. When climbing, one carabiner is clipped to a point of protection, for instance a bolt hanger or camming device. This carabiner is usually able to move freely within the sewn sling to reduce the 'pull' on the protection. The other carabiner is clipped to the rope. This end is often secured within the sling by a tight rubber 'tadpole' which prevents the carabiner from twisting, 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. ‌

Traditional climbing with quickdraws

For traditional climbs, quickdraws with lightweight wiregate carabiners 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.

Sport climbing with quickdraws

For sport climbs, quickdraws with sturdy solid gate carabiners are the norm. Chunky carabiners put up with constant abuse and regular falls. Wider slings are much easier to hold when working routes and hauling back to your high point. 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 sports routes might require far more. Guidebooks often give the number of bolts for any route so you can check you have enough before setting off.

How carabiners are made

Climbing carabiners 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 carabiners 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 carabiners. 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 carabiners. Hot forging can provide lighter weight units with no strength compromise.

Anodising

Once the carabiner 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.

Strength ratings

Statistics

Every climbing carabiner 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. ‌ Carabiners are rated in kiloNewtons (kN), a measure of force. It's hard to visualise this dynamic measurement; if your carabiner 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 carabiner would hold a static load of 2.5 metric tons.

Testing

Every climbing carabiner 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. ‌ Carabiners are rated in kiloNewtons (kN), a measure of force. It's hard to visualise this dynamic measurement; if your carabiner 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 carabiner would hold a static load of 2.5 metric tons.

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