High-Speed Steel (HSS) Fractional Twist Drill Bit Set with Metal Index Case

This item is a set of high-speed steel (HSS) twist drill bits, housed within a robust metal index case. The drill bits exhibit a dark, possibly bronze or black oxide, finish, common for HSS bits to enhance hardness and lubrication. There are at least eight discernible drill bits of varying diameters, each meticulously organized in its dedicated slot within the case. The case itself appears to be constructed from stamped sheet metal, possibly steel or aluminum, given its greyish-silver coloration and visible signs of wear, including scuffs, scratches, and potentially some surface oxidation or grime, indicating regular use. The design of the case features a hinged lid, which is visible on the right side, suggesting it closes securely to protect the bits. Below each drill bit slot, numerical markings indicate the size of the bit. These markings are presented in both fractional (e.g., 13/32, 27/64, 7/16, 29/64, 15/32, 31/64, 1/2) and decimal equivalents (e.g., .406, .422, .437, .453, .469, .484, .500). One noticeable marking is '25' near a slot, which might denote the total number of bits the case accommodates or a specific bit size. Some of the drill bits show signs of wear, particularly around their flutes, with discoloration or slight material loss visible, which is typical for used cutting tools. The overall condition suggests a working set rather than a new or pristine one, hinting at an estimated age of several years, likely from the mid to late 20th century or early 21st century, given the standard form and materials. There are no obvious maker's marks or signatures visible from this angle, but the organization and robust construction indicate a professional-grade tool set designed for durability and ease of use in workshops or industrial environments. The craftsmanship is utilitarian, focused on function and longevity.