Flax fiber (natural) vs Aramid fiber (Kevlar 49)

Every value below is a typical room-temperature figure with its source, test method and conditions — the same dataset that drives the calculators.

Flax fiber (natural) in fullAramid fiber (Kevlar 49) in full← All materials
PropertyFlax fiber (natural)Aramid fiber (Kevlar 49)Difference
Density1.5 g/cm³1.44 g/cm³Flax fiber (natural) — 4% higher
Young's modulus E58 GPa131 GPaAramid fiber (Kevlar 49) — 2.3× higher
Tensile strength800 MPa3620 MPaAramid fiber (Kevlar 49) — 4.5× higher
  • Pickering, Efendy & Le, Composites Part A 83 (2016) — natural fibre review
  • Daniel & Ishai, Engineering Mechanics of Composite Materials, 2nd ed.

Typical room-temperature values for learning and preliminary design; grades vary widely and a supplier datasheet always overrides a textbook figure. Confirm against the datasheet before design work.