Internal Measuring Tools Appraisal

Telescoping Gauge Set

This item appears to be a set of telescoping gauges, likely used for precise internal measurements of bores or holes. The set consists of multiple individual gauges, varying in length and diameter, housed within a rectangular, open-top cardboard box. The gauges themselves are made of metal, likely hardened steel, exhibiting a shiny, silver-gray surface suggesting a polished or ground finish. Some of the gauges feature knurled sections near one end, possibly for gripping or adjusting, and distinct spherical or cylindrical measuring heads at the other end. The overall condition of the gauges seems to be good, with no obvious signs of significant rust or corrosion, though some minor surface wear or smudges are visible. The cardboard case shows signs of age and use, with discoloration, scuffs, and possibly some minor structural deformation. The manufacturing details are not clearly visible on the tools themselves, but a separate piece of paper in the image mentions "United Drill Bushing" and provides specific dimensions (I.D. and O.D.), indicating a connection to drill bushings, and suggesting these gauges might be used to inspect or measure them. The presence of this label suggests a mid-20th century to late-20th century manufacturing period. The craftsmanship appears to be industrial standard for precision tools, emphasizing accuracy and durability.