In this activity you will make a keychain used to check the size/threads of popular screws used in robotics. More specifically it will check threads for ¼-20, 10-32 and 8-32 screws. This project will also develop your skills in measurement and tool use including - Compound Square, Vertical Band Saw, Hammer and Punch, Drill Press, Belt Sander, and Taps. Please note that if a team works with mostly metric screws, it would be relatively simple to drill and tap metric screw sizes with the same design below.