Nylon Used to Beryllium the most popular material to create seat belts. However, it stretches easily. It is also more prone to wear and tear. Since tiny abrasions and damage can significantly make seat belts less effective, the seat belt material used today is replaced with polyester. For the reasons http://pandora.nla.gov.au/external.html?link=https://www.ledteks.com/seatbelt-and-safety-belt-webbing