What type of hardware is often used for attaching two pieces of rigging together?

Connectors or carabiners are the appropriate hardware for attaching two pieces of rigging together due to their design and functionality. They are specifically engineered to facilitate quick attachment and detachment while providing a secure connection under load, which is crucial in rigging applications where safety and reliability are paramount. Over time, connectors and carabiners have been standardized in both their materials and testing to ensure they can handle the dynamic loads encountered in theatrical rigging environments.

While bolts and nuts provide strong connections, their use is typically more permanent and may require tools for assembly and disassembly, which is less suitable for applications that demand flexibility. Screws and anchors are primarily meant for securing objects to surfaces rather than joining rigging components. Cables and ropes, while important in rigging, require additional hardware (like connectors) to effectively join them together in a secure manner. Thus, connectors or carabiners represent the most practical choice for the specific need of linking rigging items efficiently and safely.