Adjustable Protractor Value Guide

This 1930-1950 American-made adjustable protractor represents a pivotal era in drafting history when precision metalwork replaced earlier brass and ivory designs. These versatile tools were essential for mid-century engineers and architects, offering a durable solution for complex angle measurements in surveying and construction planning.

What Is Adjustable Protractor Worth?

The typical price range for Adjustable Protractor is $25 - $40 based on recent sales. However, values can vary depending on the item's condition, rarity, and other factors such as:

• Overall condition of the metal, including the presence of rust, pitting, or significant scratches.
• The smooth functionality of the adjustable arm and the tightness of the locking screw.
• Clarity of the measurement markings and any original manufacturer branding or logos.
• Market demand for mid-century American drafting instruments, typically ranging from $25 to $40.

How to Identify Adjustable Protractor?

• Check for United States manufacturing marks and patent dates consistent with the 1930-1950 era.
• Examine the material composition, which should be industrial-grade steel or aluminum rather than modern plastic.
• Verify the presence of the original adjustment locking mechanism used to secure specific angles.
• Look for finely etched or stamped degree scales that remain legible despite age.

History of Adjustable Protractor

Protractors have been essential tools for engineers, architects, and draftsmen for centuries. Early versions were often made of brass or ivory. As manufacturing advanced, aluminum and steel became common, allowing for more precise and durable instruments. This type of adjustable protractor represents a significant step in making angle measurements more versatile for various applications, from navigation to construction planning.