What shape do D-shaped carabiners utilize for added strength?

D-shaped carabiners are specifically designed in a shape that maximizes strength and efficiency. The key feature of the D-shape is that it allows for the load to be positioned along the spine of the carabiner, which is the strongest part. This design helps distribute the force more evenly, enhancing the overall strength of the carabiner when subjected to loads.

The D-shape also allows for a more compact form, which can be beneficial when connecting multiple items or during rescue operations where space might be limited. Additionally, the shape helps to minimize cross-loading, which can occur if the carabiner is oriented incorrectly under load. This further reinforces why D-shaped carabiners are often the preferred choice in climbing and rescue situations where safety is a priority.

In contrast, other shapes such as circular, square, or triangular do not provide the same efficiency in load-bearing and can lead to ineffective force distribution or increased risk during load application.