Build stuff? Well than you need Wonderbolt.
Designed to be the fastest and easiest way to measure, identify, and cross-reference threaded fasteners, Wonderbolt gives craftspeople of any skill level the upper hand.
Measure both US and metric bolts and screws, including the outer diameter, length and thread count. For that quick project fix, Wonderbolt provides all the information needed to make hardware store purchases confidently, or easier yet, place a correct order online.
If that were not helpful enough, Wonderbolt also provides relating information from five different reference charts for a measured size. Skip the familiar hit-or-miss attempts for the right sized tool! Wonderbolt can offer the correct socket or Allen wrenches, provide decimal equivalents in both inches and millimeters, or assist in visualizing the appropriate drill bit size for a clearance hole.
Unfortunately, Wonderbolt wont tell you if its the right bolt for the job. Thats up to you. Click here for more info:
http://bryteworkapps.com/wonderbolt-terms-and-conditions/