Carbon fiber (AS4) 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.

Carbon fiber (AS4) in fullE-glass fiber in full← All materials
PropertyCarbon fiber (AS4)E-glass fiberDifference
Density1.79 g/cm³2.54 g/cm³E-glass fiber — 42% higher
Young's modulus E231 GPa72.4 GPaCarbon fiber (AS4) — 3.2× higher
Tensile strength4447 MPa3450 MPaCarbon fiber (AS4) — 29% higher
  • Hexcel HexTow carbon fiber product datasheet
  • 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.