From the Manufacturer
25-Piece Combination Hex Key Set, with Standard and Metric, includes Long / Short .050 - 3/8-inch, 1.3-- 10. Tools are made from premium grade 8650 alloy steel, heat treated and tempered, with a black oxide finish. Includes a storage pouch. Irwin tools are made of only the finest materials, manufactured to exacting tolerances. **Long / Short .050-, 3/8-, 1.3 - 10; 12-inch sizes, long series: .050- to 3/8- and 12-metric sizes, short series: 1.27mm to 10mm.
