Elongation is a measure of how far a sample will stretch before it breaks. The result is normally expressed as a percentage, also known as percent elongation (% elongation). A known gauge length is critical to performing accurate elongation calculations. The gauge length consists of two measurement points. The first is the starting distance between the upper and lower grip edges. The second point is the distance travelled by the grips when the sample breaks. Elongation is calculated by dividing the distance travelled by the original gauge length. Many standards require elongation to be measured. United offers a large selection of equipment that will help you achieve accurate and repeatable results if you are considering performing this type of test.