Screw-on and bolt-on climbing holds are two common types of holds used on indoor climbing walls. Each type has its own advantages and disadvantages, and the choice between them depends on various factors including the type of climbing wall, the intended use, and personal preferences. Here's a comparison of screw-on and bolt-on climbing holds:

1. Installation Method:

   • Screw-On Holds: These holds are designed to be attached to the climbing wall using screws. They have pre-drilled holes that allow for easy and secure attachment. Screw-on holds are typically considered more permanent and may require more effort to install, but they provide a solid and reliable connection to the wall.

   • Bolt-On Holds: Bolt-on holds use a t-nut that is attached directly onto the climbing wall. They are easier and quicker to install than screw-on holds, making them a good choice for gyms that frequently change their routes or holds. Bolt-on holds are less permanent and can be moved more easily.

2. Flexibility and Route Setting:

   • Screw-On Holds: These holds offer more flexibility for route setters since they do not rely on a t-nut having to be in the exact postion wanted. 

   • Bolt-On Holds: Bolt-on holds are easy to move, making them ideal for frequent route setting changes. Gyms that aim to keep routes fresh and challenging tend to use bolt-on holds because they allow for quick adjustments.  However, there must be t-nut pre-installed where the hold is to be installed.

In summary, the choice between screw-on and bolt-on climbing holds depends on the specific needs of the climbing wall and the preferences of the route setters and climbers. Screw-on holds offer durability and a more permanent attachment, while bolt-on holds provide flexibility for frequent route setting changes and cost savings. Many climbing gyms use a combination of both types to balance the benefits of each.