Machine Solutions Radial Force Testing Devices are specified in ASTM Standard F3067 – 14 Radial Loading Guidelines for Balloon-Expandable and Self-Expanding Vascular Stents as the device of choice for collecting radial or hoop forces from stent-like devices. MSI's patented compression technology is used to compress cylindrical stents and measure diameter change and hoop force. This provides properties including radial stiffness and strength, chronic outward forces during expansion, and radial reaction forces.