Understanding Carabiner Strength
The spine or back bar is the longest part of the carabiner and its strongest section. Carabiners display three strength ratings:
- Major Axis: The strength when loaded along the length with the gate closed. This is the strongest position. - Minor Axis: The strength when loaded across the width with the gate closed. This is considerably weaker. - Gate Open: The strength when loaded lengthways with the gate open. This is also significantly weaker than the major axis.Always look for the appropriate CE, EN and/or UKCA markings to ensure the carabiner is certified for climbing.
Carabiner Gates
The gate allows you to clip ropes, slings and protection into the carabiner. There are several different designs.
Straight gates are commonly used for clipping bolts and protection, while bent gates make clipping the rope easier and are frequently found on quickdraws.
Wire gates are lightweight and particularly popular for trad climbing, mountaineering and alpine climbing. They are less likely to freeze in winter conditions and are less susceptible to gate flutter during a fall.
The shape of the nose is also important. A snag-free nose makes clipping easier and reduces the risk of ropes or slings catching in the gate mechanism.
Choosing the Right Shape
Different carabiner shapes are designed for different applications:
D-shaped carabiners naturally position the load along their strongest axis and are versatile for attaching equipment, protection and devices.
Oval carabiners have a symmetrical shape that provides balanced loading and are particularly useful with pulleys and other equipment.
Pear-shaped carabiners have a larger capacity, making them useful for belaying and accommodating bulky knots or multiple connections.
Wide-opening carabiners provide a large gate opening and are useful for applications such as connecting to anchors, wires and via ferrata systems.
Locking Carabiners
Locking carabiners provide additional security for applications where accidental gate opening could be dangerous.
Screwgate carabiners require the user to manually close and check the locking sleeve. They are simple, reliable and widely used for belaying, anchors and protection.
Triple-action autolocking carabiners automatically lock and are designed to reduce the chance of accidental opening. They are particularly useful where additional security is required, although they are generally heavier and more expensive.
Twistlock carabiners are commonly used for via ferrata and rope-access applications. They should not automatically be considered a replacement for a screwgate, as movement from ropes or contact with rock can potentially affect the locking mechanism.
Does Weight Matter?
A lighter carabiner can help reduce the weight of your climbing rack, but lighter isn't always better. Ultralight models can be smaller and more difficult to operate while wearing gloves. They may also use narrower aluminium, which can affect durability and rope wear.
Consider strength, size, durability and ease of use alongside weight.
Carabiner Colour
Colour can be useful for organising your rack. Different colours can help you quickly identify specific carabiners or distinguish between different pieces of equipment, particularly when climbing multi-pitch routes.
Inspection and Maintenance
Regularly inspect your carabiners for excessive wear, sharp edges, deformation, corrosion or damage. Check that the gate opens and closes smoothly, springs fully shut and that locking mechanisms operate correctly.
Carabiners can be cleaned with water up to 30°C and mild detergent using a soft brush. Rinse thoroughly and allow them to air dry. Moving parts can be lubricated with a suitable lubricant according to the manufacturer's recommendations.
Store carabiners away from direct sunlight, heat and chemicals, ideally somewhere dry and well-ventilated.
Choosing Your Carabiners
Think about the type of climbing you do and the job each carabiner needs to perform. If you climb in winter, try operating your chosen carabiners while wearing gloves. Check that locking mechanisms are easy to use and that the carabiner feels comfortable in your hand.
Most importantly, always use certified climbing carabiners correctly and inspect them regularly. The right combination of shape, gate type, locking system, strength and weight will give you a reliable and versatile climbing rack.