What tool is used for securely gripping a pipe or fitting during assembly?

A nipple chuck is specifically designed for securely gripping a pipe or fitting during the assembly process. It features jaws that firmly hold the object, allowing for controlled maneuvering and adjustment without slipping or damaging the material. This is critical in pipefitting, where precision is essential for ensuring proper alignment and connections.

In contrast, a flange spreader is used to create space between two flanged components, making it easier to assemble or disassemble them. While it aids in the process, it does not grip pipes or fittings. A power drive is utilized to power various tools for threading or cutting but does not serve the purpose of gripping. Similarly, a gear threader is designed for cutting threads onto pipes and fittings but lacks the gripping capabilities required for assembly tasks. Thus, a nipple chuck stands out as the appropriate tool for securely holding pipes and fittings during assembly.