In the United States, a "quarter" is a common informal term used to refer to a quarter of various units of measurement, such as a quarter of a dollar, a quarter of a year, or a quarter of other divisible quantities. However, when used in the context of weight or mass, a "quarter" typically refers to a quarter of a hundredweight (cwt).
Since a hundredweight (cwt) in the United States is equal to 100 pounds (lbs), a quarter of a hundredweight is equal to:
1 quarter (US) = 25 pounds (lbs)
So, when you see "quarter" used in the context of weight or mass in the United States, it generally means 25 pounds. This term is often used informally, especially in agricultural or trade contexts, to refer to a convenient fraction of weight.
Grain: The grain is a unit of mass primarily used for measuring the weight of small objects or quantities, especially in the context of bullets, ammunition, and some food products. One grain is approximately equal to 0.0648 grams.