In the scenario of a vehicular crash, seat belt webbing is subjected to dynamic forces that could reach several thousand pounds. Its engineering must, therefore, balance two fundamental properties: strength and flexibility. Use a heavy-duty machine for thick fabrics. Load your machine with thread that is suitable for seat belts. https://william-ennis-2.federatedjournals.com/the-best-side-of-federal-motor-vehicle-safety-standard-seat-belt-webbing