After the rope, the humble karabiner (sometimes spelt 'carabiner') is the second most import link in your climbing equipment.

Karabiner styles

After the rope, the humble karabiner (sometimes spelt 'carabiner') is the second most import link in your climbing equipment. Karabiners are generally of an offset D design, meaning that the spine (the bar opposite the gate) where the karabiner has greatest strength, takes all the force of a fall.

The other common shape is the HMS, a pear-shaped 'biner (generally a locking design) that has a large gate opening, and designed originally to be used in conjunction with the Italian hitch (munter) knot for belaying. Beyond this there are several other karabiner shapes including oval and straight D, but these are either specialist, or just plain old-fashioned, designs.

Non-locking karabiners

Also known as krabs (or crabs), snapgates, snap-links or biners, these are the basic karabiners on your rack. They are your primary attachment to protection, used in conjunction with slings and extenders, and for racking gear on your harness. These can be sub-divided into three categories.

Straight gates, also known as plain gates, these are simple 'plain-Jane' biners that are the backbone of most racks. They come in a wide range of prices and styles, and are a good foundation biner when starting out. Their only limitation is that sometimes they can be awkward to clip.

Bent gates are designed to make rope climbing easier. These karabiners are only to be used on the rope end of quickdraws or on the tapes of cams, slung nuts, etc. They have a secondary benefit, since they are never clipped into wires, pegs or bolts they remain rope friendly, with no damaging nicks or gauges to damage the rope. Take care when clipping the rope into the biner so as ensure the rope will not become unclipped accidentally. Wire gates are definitely the 21st century karabiner: set to replace both straight and bent designs with its simple twisted gate making it stronger, lighter and safer. The stainless steel wire gate shaves several grams off the overall weight, limits gate 'chatter' and whiplash (where the gate opens during a fall reducing the krab's strength) and makes it less prone to sticking due to corrosion or cold. Once used, few users revert to traditional solid gate designs.

Locking Karabiners (see also 'Locking & belaying karabiners' article)

Screw-gates are the most common locking krabs. A simple metal collar locks the biner shut and they are most commonly used for high load situations, as connections to primary anchors and when becoming accidentally unclipped could be dangerous (e.g. belaying, important runners, etc).

In a twist-locking (or auto-locking) carabiner, the simple metal collar is replaced with a large self-locking collar to keep the biner locked.

Quickdraws A quickdraw consists of two non-locking karabiners - one straight gate (wall end) and one bent or wire gate (rope end) - joined by a short piece of tape, known as the extender. The karabiners are usually set up with their gates facing in opposite directions to make correct clipping into the rope much easier.

Which to use? 

• For sport climbing, easy clip biners (bent or wire) on the rope end of the quickdraw, that have a good gate open strength and a robust top crab for bolt clipping, are best.
• For traditional climbing, a large amount of lightweight but strong karabiners (wire gates) will often be required. Throw in several small screwgates for belays and important runners.
• Most climbing walls have in-situ karabiners and quickdraws, otherwise same as sport.