Fiber comparison
Basalt fiber vs S-2 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.
| Property | Basalt fiber | S-2 glass fiber | Difference |
|---|---|---|---|
| Density | 2.67 g/cm³ | 2.46 g/cm³ | Basalt fiber — 9% higher |
| Young's modulus E | 89 GPa | 86.9 GPa | Basalt fiber — 2% higher |
| Tensile strength | 2900 MPa | 4890 MPa | S-2 glass fiber — 69% higher |
Where these numbers come from
- Fiore et al., Composites Part B 74 (2015) — basalt fibre review
- AGY S-2 Glass product datasheet
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.