A screw thread, often shortened to thread, is a helical structure used to convert between rotational and linear movement or force. A screw thread is a ridge wrapped around a cylinder or cone in the form of a helix, with the former being called a straight thread and the latter called a tapered thread. A screw thread is the essential feature of the screw as a simple machine and also as a fastener. The mechanical advantage of a screw thread depends on its lead, which is the linear distance the screw travels in one revolution.
Sour cream is a dairy product with a short shelf life. Typically it is good for 2 to 3 weeks from when purchased. Always check the expiration date on the container.
The suggested serving size of sour cream is 1 tbsp. This serving size contains 31 calories, and 27 of those calories are from fat. Sour cream has less than 1 g of carbohydrates and 3 g of fat, which is 5 percent of the recommended amount per day. There are nearly 2 g of saturated fat, which is 9 percent of the amount recommended per day.