Flat tensile specimens are produced through milling, where the cutting tool removes material from a fixed blank or sheet to form the dog-bone shape defined by standards such as ASTM E8 and ISO 6892-1. This method is ideal for thin materials, plates, and laminated composites.

Round tensile specimens, by contrast, are made through turning on a CNC lathe, where the material rotates while being shaped into a controlled diameter and gauge length. They are commonly used for bar stock, machined parts, and materials that require uniform stress distribution during testing.

Each method serves a specific purpose: flat specimens are chosen for materials where thickness and surface condition are key testing factors, while round specimens are used when testing isotropic strength or bulk material performance.