Protractor Head Appraisal

Combination Square Protractor Head

This item is a protractor head, a component of a combination square set, typically used in metalworking, woodworking, and machining for measuring angles and slopes. It features a robust construction, likely made from cast iron or steel, finished in a dark gray, textured paint or chemical blackening, with machined and polished silver-colored metal components for the protractor scale. The base is flat and elongated, forming a stable reference surface that is approximately 6-8 inches in length. At its center, a circular protractor scale is visible, graduated in degrees, with numerical markings that appear to range from 0 to 180, indicating its functionality for measuring angles. A pivoting arm or blade holder, also made of metal, is present, allowing for the attachment of a rule or blade (not present in the image). This arm is secured by a knurled locking screw, designed for adjusting and fixing the angle. Integrated into the pivoting mechanism is a small, green-tinted spirit level vial, indicating its dual purpose as a level for finding true horizontal or vertical planes. The overall condition appears used but well-maintained, showing some minor wear consistent with its utilitarian nature. No apparent significant damage, rust, or repairs are visible, suggesting good structural integrity. The craftsmanship appears to be industrial standard, focusing on precision and durability, characteristic of measuring tools from the mid to late 20th century to contemporary production.