E-Glass E-CR
Grade
ASTM D578
E-CR = 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.
Values for the E-CR condition
Other E-Glass tempers and conditions
E-Glass is listed in 2 conditions; see the grade overview at E-Glass.
- STRAND
- E-CR
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 |
E-CRThis page 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 |
What is E-Glass E-CR?
E-Glass E-CR is E-Glass in the E-CR grade — 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. E-Glass E-CR has a tensile strength of 3,450 MPa (500 ksi), stronger than 100% of glass grades. Elongation at break is 4.6% and the elastic modulus is 80 GPa (11.6 Msi). E-Glass E-CR has a density of 2.66 g/cm³ (0.0961 lb/in³), heavier than 51% of glass grades. It melts at 1,065°C (1,949 °F).
Advantages
- Ductile — tolerates forming and impact — 4.6%, better than 90% of glass grades
Limitations
- Hard to polish — 60/100, worse than 81% of glass grades
E-Glass E-CR properties
Typical room-temperature values for E-Glass E-CR; 15 are specific to this condition. Other listed values are E-Glass reference data and may not represent this condition. Bars are the position among glass grades.
Physical4
E-Glass E-CR has a density of 2.66 g/cm³ (0.0961 lb/in³), heavier than 51% of glass grades. It melts at 1,065°C (1,949 °F).
Mechanical11
E-Glass E-CR has a tensile strength of 3,450 MPa (500 ksi), stronger than 100% of glass grades. Elongation at break is 4.6% and the elastic modulus is 80 GPa (11.6 Msi).
Thermal5
E-Glass E-CR is rated for continuous service to 650°C (1,202 °F). It conducts heat at 1.2 W/m·K (0.693 BTU/hr·ft·°F), worse than 58% of glass grades. Thermal expansion is 6 µm/m·K (3.33 µin/in·°F).
Electrical5
E-Glass E-CR 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 very good (80/100), better than 58% of glass grades.
Sustainability4
Producing a kilogram of E-Glass E-CR 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 E-CR's machinability is not recommended (14/100, worse than 58% of glass grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with E-Glass E-CR
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.
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.
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 |
E-Glass E-CR — frequently asked
What is E-Glass E-CR used for?
E-Glass E-CR 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-CR?
E-Glass E-CR has a typical tensile strength of 3,450 MPa (500 ksi) — stronger than 100% of glass grades. Strength varies by condition: see the 2 listed tempers.
Is E-Glass E-CR easy to machine?
Not especially — machinability is rated not recommended (14/100, worse than 58% 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 E-CR 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 E-CR?
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 E-CR 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-CR?
E-Glass E-CR is rated for continuous use to about 650°C (1,202 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.