A "link" is a unit of length that is equivalent to 1/100th of a chain. In the United States customary system of measurement, one link is equal to 7.92 inches or 0.201168 meters. It is primarily used in surveying and land measurement.
Links are often used in conjunction with other surveying units like chains and rods to measure distances on land, especially for large plots or parcels of land. The term "link" is rarely used in everyday conversation or modern applications outside of surveying and related fields. Instead, more common units like feet, yards, or meters are used for measuring length in most contexts.
A "microinch" is a unit of length used to measure extremely small distances or dimensions. It is equal to one millionth of an inch or 0.000001 inches. In scientific notation, it can be represented as 1 µin (pronounced as "one microinch").
Microinches are typically used in precision engineering, manufacturing, and industries where very fine tolerances and high levels of accuracy are required. This unit allows for the measurement of surface finishes, material thicknesses, and other minute details with extreme precision.
To put it into perspective, a microinch is much smaller than a human hair, which is typically several thousand micrometers (µm) or microns in diameter.