How to Choose the Right Carabiners

arabiners are lightweight, metal snap-links used by climbers for a wide variety of climbing tasks. They come in a range of styles, sizes and designs. To choose and use them properly, you must first understand the differences between them.

'Biner 101

Carabiners are built to connect things together; whether it's a climber to her rope, a rope to a piece of protection or a collection of protection pieces to a climbing harness. They're strong, because they have to be able to withstand extreme forces (and because lives often depend on them). They're light so that climbers carry a bunch of them without getting weighted down.

Different climbing tasks require different kinds of carabiners. The variables that typically distinguish styles include shape, gate-type, strength, weight and size.

Step #1: Consider Your Shape Options

		Oval-- Oval carabiners are the original style. They're versatile and affordable, though not quite as strong as other shape options. Oval 'biners have smooth, uniform top and bottom curves to limit load shifting.
		"D"-Shaped-- D-shaped 'biners are designed to shift weight loads toward the spine (the strongest part of the 'biner) and away from the gate (the weakest part). As a result, they have excellent strength-to-weight ratios. Ds are lighter and stronger than ovals of the same size and material. Because of their shape just above the gate, they are also easier to clip into protection pieces.
		Asymmetrical "D"-- Asymmetrical Ds work like regular Ds, but they're slightly smaller at one end to further reduce weight. Asymmetrical 'biners generally have larger gate openings than regular Ds, which makes clipping them even easier. But they don't have as much inside room as similarly-sized Ds or ovals.

Step #2: Consider Your Gate Options

		Straight- Standard straight gates are by far the most common type. They're perfectly straight from pivot point to end. Like most other types, they're spring-loaded to open easily when pushed, but rotate closed automatically when released.
		Bent-gate-- Bent-gate 'biners have concave gates designed to make clipping into protection easier. The bent-gate design does not significantly affect the 'biner's strength or its weight. But if not used properly, bent-gate 'biners can unclip from your rope. As with any other kind of climbing equipment, you must learn how to use bent-gate 'biners correctly in order to be safe. NOTE: Bent gate carabiners should only be used on the end of the quickdraw or runner which the rope clips into. Never clip them directly to the protection.
		Locking-- Locking 'biners have gates that can be locked in the closed position to provide extra protection against accidental gate-openings. They should be used anytime you depend on a single carabiner for safety, such as during a rappel, while belaying, or at your first piece of protection. Locking 'biners can be oval, D-shaped or asymmetrical. The locking devices themselves range from simple threaded collars that screw down over the gate to spring-loaded, "automatic" mechanisms. Wire-Gate-- Wire-gate 'biners use a loop of stainless steel wire for a gate. This wire loop creates its own spring mechanism as it pivots, decreasing overall weight and eliminating the need for extra parts found in conventional gates. Wire gate designs also allow for larger gate openings. Although wire gates don't appear as strong as conventional styles, most are. They are also less likely to vibrate open during a fall due to the lower mass in the gate itself.

Step #3: Consider Your Needs

The most important factor to consider when choosing carabiners is what you'll be using them for. Different styles are designed for different tasks. If you're just starting out, ask a climbing instructor or an experienced salesperson for guidance on which styles to start with. If you're a more experienced climber, consider the kinds of climbing you want to do, the kinds of protection you'll be clipping into and the kinds of tasks you'll need your 'biners to perform.

Step #4: Don't Forget Overall Performance

Strength
Carabiners are designed to be loaded along their long ("major") axis with their gates closed. When loaded correctly, all of the carabiners that REI carries are built strong enough to handle the loads found in normal climbing situations.

Unfortunately, carabiners can fail at loads well below their rated strength when they're used incorrectly or if they're loaded with their gates open.

Gate Lash
The dynamics of just about any climbing fall can cause "gate lash" (a momentary opening of a carabiner's gate caused by vibration or the spine hitting a solid object). Gate lash can reduce a 'biner's overall strength to its open-gate strength. It can occur when:

A gate's inertia overcomes the spring tension holding it in place
A gate collides with another object

To protect yourself against this type of carabiner failure, choose carabiners with locking gates and/or high gate-open strengths (REI provides both gate-closed and gate-open strength ratings for your convenience) and more importantly, learn how to use your carabiners correctly. Specific gate designs and/or stiff spring tensions may also reduce the risk of gate lash. Ask an experienced REI salesperson for recommendations.

NOTE: Because a falling climber is a mass accelerating under the pull of gravity, carabiner strengths are measured in kiloNewtons (kNs), a measure of force (mass times acceleration). For conversion purposes, 1 kN is approximately equal to the force of 225 lbs.

Weight
In general, the less weight you carry with you as you climb, the better. But lighter carabiners are not always better than heavier ones. Super-light carabiners often use narrower rod stock, which can result in lower gate-open strengths and shorter life spans. Narrow 'biners can also cause more rope wear, since the narrow ends can act like edges, biting into your weighted rope as it slides past.

Size
Carabiners also come in a variety of sizes. Large 'biners are typically easier to handle, easier to clip (they have larger gate openings) and can hold more gear inside. They are commonly used with belay and rapel devices. Smaller 'biners are lighter and take up less room on your rack.

Step #5: Get a Feel for Your Options

Once you've narrowed down your search to a handful of carabiner styles, grab a few examples and get a feel for how they fit in your hand, how easy they are to clip and unclip, and how smoothly the gates work. If you're looking at a locking 'biner, try locking and unlocking the gate a few times (with one hand). Choose models that feel good, operate smoothly and are easy to work with.

Safety Tip: Inspecting Your Carabiners for Damage

Check all surfaces of your carabiners for cracks, sharp edges, corrosion, burrs or excessive wear. Even hairline cracks can reduce 'biner strength by more than 50%.
Check each gate to make sure it opens and closes quickly and easily. Be sure all gates (and any locking mechanisms) close freely and completely.
Make sure no rivets are bent or missing.

If any of your carabiners don't pass the above inspection, remove them from service and destroy them. Also retire any carabiner that has been dropped a significant distance (over 20 feet), especially if its gate ceases to function properly. Dropped 'biners can suffer significant damage yet still appear intact. If you are unsure about the condition of any 'biner that has been dropped, consult a climbing expert for advice before using it again.

Safety Tip: Basic 'Biner Care

To get the most out of your carabiners, keep them clean and free of grit. If you notice a sticky gate, wash it in warm, soapy water, rinse it thoroughly and lubricate it with dry graphite WD40 or a similar lubricant around the hinge area, the spring hole and the locking mechanism. Be sure to wipe off all excess lubricant. Don't store your 'biners in humid or salty air, with damp equipment or clothing, or near corrosive chemicals. Don't file your carabiners for any reason (sand down burrs with 220-400 grade sandpaper. If this doesn't remove the burr, destroy the 'biner).