A square mil (abbreviated as sq mil or mil²) is a unit of area measurement used primarily in the United States for very small areas, especially in the context of electrical engineering and wire gauge measurements. One square mil is equal to one square thousandth of an inch or one square mil (0.000001 square inches).
In terms of modern metric units, one square mil is approximately equal to 6.4516 square micrometers (µm²) because there are 25.4 micrometers in one thousandth of an inch (1 mil).
Square mils are often used when specifying the cross-sectional area of wires, particularly in electrical and electronic engineering. For example, the American Wire Gauge (AWG) system uses square mils to represent the cross-sectional area of wires, with smaller wire sizes having fewer square mils, and larger wire sizes having more square mils.
The "vara conuquera cuadrada" is another historical unit of land area measurement used in some Spanish-speaking countries, particularly in parts of Latin America. Like the "vara castellana cuadrada," it measures land area in square varas, but it is a regional variation and not part of the standard metric system.
The exact length of the "vara conuquera cuadrada" can vary by region, but it is generally close to 100 square varas, with each square vara having a specific length determined locally. The term "conuquera" is associated with the conuco, a type of small-scale agricultural plot traditionally used in some Latin American countries for subsistence farming.
As with other historical units of measurement, the use of the "vara conuquera cuadrada" is not standardized and is mostly a part of local customs and traditions. Official land measurements and land records in many Spanish-speaking countries have transitioned to more standardized systems, such as metric units, for land area measurements.