Name of the Tool
- Brown & Sharpe 0–25 Micrometer
- Also known as a micrometer screw gauge or outside micrometer
- Designed for precision measurement of external dimensions
Manufacturer
- Created by Brown & Sharpe
- Founded in Providence, Rhode Island, USA
- A historic American company renowned for high-precision measuring instruments
Time Period of Origin
- Micrometers of this type were produced mainly from the early to mid-20th century
- The Brown & Sharpe brand itself dates back to 1833
- This specific 0–25 mm (or 0–1 inch) model reflects mature industrial design from the 1920s–1950s, when precision machining rapidly expanded
Who Created It
- Developed by engineers and toolmakers at Brown & Sharpe
- The micrometer design evolved from earlier precision concepts pioneered in the 19th century
- Brown & Sharpe played a major role in standardizing measurement tools used worldwide
Primary Function and Use
- Used to measure outside dimensions with extreme accuracy
- Common measurements include:
- Shaft diameters
- Metal or wooden thickness
- Machined parts in lathes and mills
- Typical accuracy:
- Up to 0.001 inch (or 0.01 mm) depending on the model
Key Components
- U-shaped steel frame – provides rigidity and stability
- Anvil and spindle – contact points for the measured object
- Knurled thimble and ratchet – allow controlled, consistent pressure
- Engraved scale markings – ensure precise readings
Materials and Construction
- Made from hardened steel and stainless steel
- Designed to resist wear, corrosion, and thermal expansion
- Built for decades of professional use
Industries That Used This Tool
- Machining and metalworking
- Lathe and milling operations
- Engineering and manufacturing
- Woodworking requiring fine tolerances
- Tool and die making
Why It Is Considered Antique and Valuable Today
- Represents the golden age of American industrial craftsmanship
- Known for durability, mechanical precision, and reliability
- Highly collectible among:
- Machinists
- Engineers
- Vintage tool collectors
- Still fully functional despite its age
Historical Significance
- Micrometers like this helped shape:
- Mass production
- Interchangeable parts
- Modern engineering standards
- Brown & Sharpe tools were trusted in factories, shipyards, and workshops worldwide
