Which method tests a material's toughness by using a pivoting arm to strike it?

The method that tests a material's toughness by using a pivoting arm to strike it is the Izod test. This test involves a notched sample of the material being clamped at one end while a weighted pendulum strikes the free end. The energy absorbed by the material during the fracture is measured, which provides an indication of its toughness. The design of the Izod test, with its striking mechanism and clamping setup, allows for the evaluation of the material's resistance to impact, specifically how it behaves when subjected to sudden forces. This makes it particularly useful for assessing materials that may be subject to sudden or unexpected impacts in real-world applications.

In contrast, other methods mentioned serve different purposes. The Charpy test also measures toughness but has a different setup and involves a different type of notch and impact orientation. The tensile test evaluates the strength and ductility of materials under axial loads, while the compression test assesses how materials behave under compressive forces. Each of these tests is tailored to provide insights into specific mechanical properties, which is why the context of the Izod test is distinct as it focuses on the impact resistance and toughness of materials.