BoltSize-It - Bolt and Nut Checker 

Size bolt diameter by pushing bolt through sizing holes

Gauges hex nuts and washers (USS, SAE)

Gauges metric hex nuts and washers by holding under metric holes

Measure US and metric thread pitch

Special notch gauges flat headed metal and wood screws

Ruler marked with inches and millimeters

Sturdy and lightweight plastic resists water, alcohol, oil, and grease

Fits in shirt pocket (8-5/8" x 3-1/4" or 217 mm x 82 mm)