E-Glass
ASTM D578
E-Glass is an alumino-borosilicate reinforcement fibre covered by ASTM D578, the general-purpose glass fibre for polymer composites and PCB laminates.
Reference datasheet — E-Glass is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
E-Glass tempers and conditions
E-Glass is supplied in 2 conditions, soft to hard.
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Impregnated strand / direct roving | Pick these de-rated values when specifying commercial roving, yarn or fabric, where handling damage and strand statistics cut usable strength by 30–40 %. | 2,100 | 3 | 600 HV | 1 W/m·K | |
Boron-free corrosion-resistant E-glass | Choose for acid-exposed GRP pipe, tanks and rebar, or where boron-free melting is required; slightly higher modulus and service temperature, marginally higher cost. | 3,450 | 4.6 | 650 HV | 1 W/m·K |
Supply forms, finishes and certifications
Ways E-Glass is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
FILDefault | Virgin continuous filament | Printing process |
What is E-Glass?
E-Glass is an alumino-borosilicate reinforcement fibre covered by ASTM D578, the general-purpose glass fibre for polymer composites and PCB laminates. Engineers specify it for good electrical insulation, 3400 MPa filament tensile strength and 73 GPa modulus at low cost; it is supplied as continuous filament, strand, roving, chopped strand, mat, woven fabric and prepreg. Corrosion resistance is only moderate (62/100), with the E-CR variant used for acid service; elongation is 4.8 % and the fibre service ceiling is about 550 °C. S-glass is the step up when strength and stiffness govern. E-Glass has a density of 2.58 g/cm³ (0.0932 lb/in³), lighter than 61% of glass grades. It melts at 1,065°C (1,949 °F). E-Glass has a tensile strength of 3,400 MPa (493 ksi), stronger than 98% of glass grades. Elongation at break is 4.8% and the elastic modulus is 73 GPa (10.6 Msi).
What is E-Glass used for?
- FRP composites
- PCB substrates (FR4)
- Wind turbine blades
- Insulation
Advantages
- Ductile — tolerates forming and impact — 4.8%, better than 91% of glass grades
Limitations
- Hard to polish — 60/100, worse than 81% of glass grades
E-Glass properties
Typical room-temperature values; bars are the position among glass grades.
Physical4
E-Glass has a density of 2.58 g/cm³ (0.0932 lb/in³), lighter than 61% of glass grades. It melts at 1,065°C (1,949 °F).
Mechanical11
E-Glass has a tensile strength of 3,400 MPa (493 ksi), stronger than 98% of glass grades. Elongation at break is 4.8% and the elastic modulus is 73 GPa (10.6 Msi).
Thermal5
E-Glass is rated for continuous service to 550°C (1,022 °F). It conducts heat at 1.1 W/m·K (0.636 BTU/hr·ft·°F), worse than 68% of glass grades. Thermal expansion is 5.4 µm/m·K (3 µin/in·°F).
Electrical5
E-Glass is an electrical insulator with a dielectric strength of 12 kV/mm (304.8 V/mil) and a resistivity of 1×10¹³ Ω·m.
Chemical & Environmental2
Corrosion resistance is good (62/100), worse than 65% of glass grades.
Sustainability4
Producing a kilogram of E-Glass takes about 45 MJ of energy and emits 2.6 kg of CO₂ — less than 58% of glass grades. Typical recycled content is 5%.
Manufacturability2
E-Glass's machinability is poor (15/100, worse than 54% of glass grades).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the glass family
Yield strength against density for every glass grade FabDigit runs. E-Glass is highlighted; hover a dot for its name, or open the interactive family chart.
Working with E-Glass
Is E-Glass easy to machine?
Extremely abrasive — cut fabric/laminate with diamond, PCD or carbide tooling, high speed and low feed, with dust extraction (respirable glass dust).
Can E-Glass be welded?
Not weldable; joining is done in the matrix (adhesive or resin co-cure of the composite), fibers themselves can only be fused above ~1100 °C.
Can E-Glass be formed, bent or molded?
Supplied as roving, chopped strand, mat or fabric for filament winding, pultrusion, SMC/BMC, RTM, hand lay-up and PCB prepreg; drapability set by weave style and sizing.
E-Glass chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| SiO2network former | 52 – 56 | 54 |
| Al2O3 | 12 – 16 | 14 |
| CaOCaO+MgO combined per ASTM D578 | 16 – 25 | 22 |
| MgO | 0 – 5 | 0.5 |
| B2O3absent in E-CR variant | 5 – 10 | 7 |
| Na2O+K2Oalkali limited for electrical grade | 0 – 2 | 0.5 |
| TiO2 | 0 – 1.5 | 0.2 |
| Fe2O3 | 0.05 – 0.4 | 0.2 |
| F2fining agent, often omitted | 0 – 1 | 0.1 |
What surface finishes work on E-Glass?
Performance depends on the silane sizing matched to the resin (amino for epoxy, methacryl for polyester/vinyl ester); heat-cleaned fabric loses ~30–50 % strength unless re-finished.
Equivalent designations
Standards and trade names that resolve to E-Glass in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- D578
How much does E-Glass cost?
E-Glass is a budget-cost glass ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
E-Glass — frequently asked
What is E-Glass used for?
E-Glass is typically used for FRP composites, PCB substrates (FR4), wind turbine blades and insulation. In short: default composite reinforcement fibre; good electrical insulation; lowest-cost structural glass fibre.
What is the tensile strength of E-Glass?
E-Glass has a typical tensile strength of 3,400 MPa (493 ksi) — stronger than 98% of glass grades. Strength varies by condition: see the 2 listed tempers.
Is E-Glass easy to machine?
Not especially — machinability is rated poor (15/100, worse than 54% of glass grades). Extremely abrasive — cut fabric/laminate with diamond, PCD or carbide tooling, high speed and low feed, with dust extraction (respirable glass dust).
Can E-Glass be welded?
Not weldable; joining is done in the matrix (adhesive or resin co-cure of the composite), fibers themselves can only be fused above ~1100 °C.
What surface finishes work on E-Glass?
Performance depends on the silane sizing matched to the resin (amino for epoxy, methacryl for polyester/vinyl ester); heat-cleaned fabric loses ~30–50 % strength unless re-finished.
Can E-Glass be formed, bent or molded?
Supplied as roving, chopped strand, mat or fabric for filament winding, pultrusion, SMC/BMC, RTM, hand lay-up and PCB prepreg; drapability set by weave style and sizing.
What is the maximum service temperature of E-Glass?
E-Glass is rated for continuous use to about 550°C (1,022 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does E-Glass cost?
E-Glass is a budget-cost glass ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM D578 Standard Specification for Glass Fiber Strands — ASTM International (2018)
- ASTM D2343 Tensile Properties of Glass Fiber Strands, Yarns and Rovings — ASTM International (2017)
- ASM Engineered Materials Handbook Vol.1 — Composites — ASM International (1987)
- Advantex / E-CR glass fiber technical data — Owens Corning (2022)
- AGY High Strength Glass Fibers technical paper (E vs S-2 Glass) — AGY (2006)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.