The drop weight test to DIN EN 10274 and API 5L is a mechanical test on metals, in which a defined weight drops onto a specimen from a specified height.
Following the drop weight test the appearance of the fracture surfaces is evaluated. Here the proportions of the deformation fracture surface and brittle fracture surface of the metal specimen are visually determined. The evaluation can also be based on the effective absorbed energy of the metal specimen.
The DIN EN 10274 drop weight test and the recommended practice 5L3 of the American Petroleum Institute (API) describe test methods for which so-called high energy drop weight testers are used. While EN 10274 describes the general test performance, API refers to a product standard for line pipes.
The test is generally performed on specimens obtained from sheet metals for pipe manufacturing or from pipes with an outer diameter larger than 300 mm and a wall thickness of more than 6 mm. In this test a specimen with a cold-pressed notch and supported at both ends is smashed, whereby the impact occurs opposite the notch. The mounting is similar to the three-point flexure test with impact load on the specimen. The energy (weight and release height) is set so that the specimen breaks and the fracture surface can be assessed visually.
In the API, a milled chevron notch is additionally described, which is primarily used for higher strength material. Here, the two standards mentioned above deviate from each other, because according to DIN EN 10274 machine manufactured notches are not permitted.
The test is performed at a predetermined temperature.