Seat Belt Webbing Seat belt webbing has been keeping us safe and secure in our cars and trucks for decades. With approximately 6,000 lbs of tensile strength, there's no need to wonder why these polyester straps have been entrusted with our lives during high-speed travel. Its strength also makes seat belt webbing useful in a variety of other applications, and SGT KNOTS Seat Belt Webbing is made from top-quality materials brought to you at an affordable price you can get all you need and use it anywhere and any time you need.