Aluminum foil is rolled into sheets so thin that traditional units like inches or centimeters do not easily convey the size. Understanding the precise thickness requires familiarity with the specialized units used by manufacturers. This knowledge clarifies the distinction between the different types of foil available for purchase, which are categorized based on their physical dimensions.
Standard Industry Measurements for Foil
The thickness of aluminum foil is quantified using systems designed for microscopic measurements. In the United States, the unit known as the “mil” is widely used, representing one-thousandth of an inch. International and technical specifications typically rely on the metric unit called the micron, also known as the micrometer, which is one-millionth of a meter.
Standard household aluminum foil generally falls within a thickness range of 10 to 18 microns. This measurement translates to approximately 0.4 to 0.7 mils, which is thin enough for light-duty kitchen tasks. Heavy-duty foil is thicker, typically ranging from 18 to 25 microns. This equates to about 0.7 to 1.0 mils, providing enhanced durability.
The Direct Conversion to Centimeters
To express these microscopic measurements in the centimeter unit, a simple conversion factor must be applied. Since one micron is equivalent to one ten-thousandth of a centimeter. The extremely small thickness of the foil is why centimeters are not the preferred unit for this specific measurement.
Standard aluminum foil, with its typical thickness of 0.0010 cm to 0.0018 cm, demonstrates this minute scale. Heavy-duty foil is slightly thicker, measuring between 0.0018 cm and 0.0025 cm. The preference for microns in the metric system is due to the convenience of using whole numbers, such as 20 microns, rather than the multiple decimal places required for the centimeter measurement.
How Thickness Impacts Foil Use
The difference in thickness between foil grades directly impacts its functional performance. Standard foil is highly flexible and easy to mold around food items. Its relative thinness, however, makes it more susceptible to tearing, especially when handling foods with sharp edges or bones. The material is primarily used to create a barrier against ambient air and light for basic preservation.
Heavy-duty foil provides better resistance to puncture and tearing, making it suitable for demanding applications. This thicker material retains heat more effectively, which is beneficial for lining roasting pans or wrapping foods for grilling. Its greater structural integrity also allows it to serve as a better insulator for freezing, protecting stored food from freezer burn. Thicker foil also offers a more robust barrier against moisture vapor transmission, maintaining food quality during extended cooking or storage times.