Kevlar is the registered trademark for a light, strong para-aramid synthetic fiber, related to other aramids such as Nomex and Technora. Developed at DuPont in 1965 by Stephanie Kwolek and Herbert Blades, it was first commercially used in the early 1970s. Typically it is spun into ropes or fabric sheets that can be used as such or as an ingredient in composite material components. Currently, Kevlar has many applications, ranging from bicycle tires and racing sails to body armor because of its high strength-to-weight ratio—famously: "...5 times stronger than steel on an equal weight basis...". A similar fiber called Twaron with roughly the same chemical structure was introduced by Akzo in 1978, and now manufactured by Teijin. Properties When Kevlar is spun, the resulting fibre has great tensile strength (ca. 3 000 MPa), a relative densi