This is your go-to tool when creating new threads. Add machine screws to just about any material from metal to wood. Use it to form new threads, re-form burred threads or clean out plaster obstructions. Each tap size rethreads to next larger size if threads are stripped.

This time saving addition to your service kit has three of the most common tap sizes (6-32, 8-32 and 10-32) on one replaceable blade.