Aramid fiber is a class of synthetic fibers known for their incredible tensile strength and heat resistance. They are made from long-chain synthetic polyamides, with para-aramid being the most common type. Aramid fibers are used in advanced products where light weight, yet high strength is needed, such as aerospace and military applications, bulletproof vests, and phone cases. Some key characteristics of aramid fibers include:

• High strength: Aramid fibers are seven times stronger than steel.
• Heat resistance: They retain much of their strength at high temperatures and resist permanent deformation or creep under prolonged stress.
• Low flammability: Aramid fibers have a very high melting point (>500 °C (932 °F)) and are low flammable.
• Sensitivity to acids and salts: Aramid fibers are sensitive to acids and salts.
• Nonconductive: Aramid fibers are nonconductive and do not impact WiFi, GPS, or phone service.

Common aramid brand names include Kevlar, Nomex, and Twaron. Aramid fibers are available as filament yarn, staple fiber, or pulp.