For large oil and gas mains, specimens from the pipe wall are subjected to a drop-weight test to API 5L. Specimens with the height of the original wall thickness and widths of several centimeters are subjected to abrupt loading via a vertically falling weight with a tup. The energy (weight and release height) is set so that the specimen breaks, allowing the fracture surface to be assessed visually. Zwick supplies drop-weight testers up to 100,000 J for this type of test.