Vintage DHH High-Speed 12-Piece Straight Shank Drill Bit Set in Metal Box

This item is a 12-piece set of high-speed steel (HSS) straight shank drill bits, contained within a utilitarian metal box. The drill bits vary in size, with a prominent stack of bits labeled as 5.0 diameter, indicating metric sizing, likely 5.0mm. The label also specifies 'DHH High Speed Straight Shank Drills NT 5XL Type 350 B 135 Split Point'. This indicates that the drills are of a specific type suited for general-purpose drilling, with a 135-degree split point for better self-centering and reduced walking on the workpiece, enhancing drilling performance and preventing skidding. The bits themselves exhibit a dark gray, almost black, finish, characteristic of high-speed steel, with visible helical flutes for chip removal. Some bits appear tarnished and show signs of use, including some oxidation and wear on the cutting edges, suggesting they are not new. The metal box holding the bits is a simple, rectangular container with a hinged lid, appearing to be made of galvanized steel or a similar robust metal. The box itself shows wear, including scratches, scuffs, and possibly minor dents consistent with a tool used in a workshop environment. The overall condition suggests a vintage or used set of tools that has seen practical application, but the core function of the drill bits should still be intact after sharpening. This set dates back to an era when tools were manufactured for durability and repairability, likely mid-20th century.