biner

A biner, short for carabiner, is a metal loop with a spring-loaded gate used to quickly connect components in rope and harness systems. The name carabiner traces back to the German term Karabinerhaken, once used on rifles and climbing hardware, and the shortened form “biner” is common in climbing and outdoor communities.

Most bins are made from aluminum or steel. Aluminum carabiners are lighter and common in sport climbing and rope access, while steel variants offer greater durability for industrial use or heavy-duty work. Finishes such as anodizing improve corrosion resistance. They are rated to carry specific forces in three directions: along the major axis, across the minor axis, and with the gate open. Typical ratings place the major-axis strength around 20–25 kN, with cross-loading and open-gate strengths lower; exact figures depend on the model and certification.

Shapes and gate types vary. Shape categories include D-shaped, offset D, oval, and pear/HMS-style bins, each influencing strength and how they seat in a system. Gate configurations include straight and bent gates, and locking versus non-locking designs. Locking carabiners use mechanisms such as screw gates, twist locks, or other auto-locking systems to prevent accidental opening. In practice, non-locking bins are common for general use, while locking variants are preferred for critical connections in climbing, rescue, and rope access.

Care and use: inspect bins for cracks, deformation, corrosion, or gate sticking before each use. Do not cross-load or subject them to impact beyond the manufacturer’s ratings. Clean with fresh water if needed and store away from harsh chemicals. Regularly retire bins that show signs of wear or prior impact.