Amazon.com: Screw Chek'r Metric Screw Thread Size Gauge No. 2 (8MM to 14MM) 1/8 Inch Heavy Gauge Steel Screw Checker, Made In USA, chrome, 02130 : Industrial & Scientific
Metric Metal Screw Thread Chek'R
Metrics in Engineering - Metric Fasteners (Screws, Nuts, Washers, and Bolts)