Thread Checker, Nut and Bolt Thread Checker, Bolt Size and Thread Gauge, Bolt and Nut Identifier Gauge, Bolt Gauge

This is a must have item for DIYers! Makes finding bolt/nut sizes easy and accurate. It’s well made and is a great value for the money! East to use and read. It’s light weight and fits well in a toolbox drawer.

This is a well-made tool, very useful for sorting that batch of miscellaneous nuts and bolts you've accumulated. However, because of its dimensions it is really only useful for sizing hardware that is loose and can be brought to the checker. If you need to size something in place, say a bolt down in an engine bay, you'll probably be better off with one of the sets with detachable pieces. For the right task, this works great.

This thread checker is accurate, well organized, and has both SAE and metric sizes clearly labeled. It makes identifying nuts and bolts much faster than trial and error, and the markings are easy to read. The only reason I’m giving it 4 stars is that I wish it included a rigid backing plate. While it can be mounted directly to the wall, that doesn’t allow it to sit perfectly flush or provide as clean and sturdy of an installation as a built-in backing would. Overall, it’s a useful tool that saves time and is a great addition to any garage or workshop.

I've not actually had to use it yet, to figure out accuracy, but I've had to take enough screws and nuts to the hardware store to check size and get a replacement. This will save me some money on those trips to the store, especially if it's a special type (prepainted, rust free, etc.) that the store doesn't have. I figured the money spent is worth saving the trips and will pay for itself.

Have you ever had to replace a screw or nut from a broken device and didn't know what size to look for? This tool allows you to to try the screw or nut against a reference to determine what it is. It has UN Fine, UN Course, and Metric examples.