Carbon fiber (AS4) vs Basalt fiber

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

Carbon fiber (AS4) in fullBasalt fiber in full← All materials
PropertyCarbon fiber (AS4)Basalt fiberDifference
Density1.79 g/cm³2.67 g/cm³Basalt fiber — 49% higher
Young's modulus E231 GPa89 GPaCarbon fiber (AS4) — 2.6× higher
Tensile strength4447 MPa2900 MPaCarbon fiber (AS4) — 53% higher
  • Hexcel HexTow carbon fiber product datasheet
  • Fiore et al., Composites Part B 74 (2015) — basalt fibre review

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.