This tool gets five stars. If you are a normal guy, you have one or more unlabeled jars or cans of screws in your shop, not to mention that sooner or later you will encounter a mystery screw that needs to be replaced. While this gauge will not give you the thread pitch for machine screws, it will give the size and length and it is particularly useful for sizing wood screws. I bought two and started using them the day they arrived. I tried them first on some screws of known sizes to best determine how the calibrations work, and you may want to do the same. These are simple and have no batteries or moving parts, they are made in the USA, and they are dead nuts accurate. Highly recommended.

Have used screw gauge a couple times Tee shirts are nice. Nuts and bolts were perfect for my application.