What type of wrench is suitable for threading polished pipes together?

A strap wrench is suitable for threading polished pipes together because it utilizes a flexible strap that wraps around the pipe without causing damage to the surface. The design minimizes the risk of scratching or marring the polished finish, allowing for secure tightening or loosening without creating marks or dents. This makes it particularly ideal for use on surfaces where aesthetics and finish are important.

In contrast, a pipe wrench, while effective for gripping and turning pipes, tends to grip with serrated teeth that could damage the polished surface. The monkey wrench and open-end wrench also lack the necessary design to protect the finish; they can potentially slip or mar the surface when used on polished pipes. Therefore, the strap wrench stands out as the appropriate choice for maintaining the integrity of polished pipes while ensuring effective threading.