Basalt fiber vs E-glass fiber

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

Basalt fiber in fullE-glass fiber in full← All materials
PropertyBasalt fiberE-glass fiberDifference
Density2.67 g/cm³2.54 g/cm³Basalt fiber — 5% higher
Young's modulus E89 GPa72.4 GPaBasalt fiber — 23% higher
Tensile strength2900 MPa3450 MPaE-glass fiber — 19% higher
  • Fiore et al., Composites Part B 74 (2015) — basalt 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.