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E-44 GF

Reinforced grade

GF = glass-fibre reinforced laminate / FRP

Structural laminates, tanks, insulating boards — huge strength gain but anisotropic and abrasive to tooling.

Standard cost $$

Values for the GF condition

Other E-44 grades and fills

E-44 is listed in 9 conditions; see the grade overview at E-44.

Compare all 9 grades and fillsHide
Grade · open for datasheetBest forYield MPaTensile MPaElong. %Hardness
Conductive / ESD filled
Static-dissipative floorings, coatings and potting where charge build-up must be avoided.—451.288 Shore D
Rubber-toughened
Pick when peel strength and crack resistance matter more than stiffness and heat resistance — structural adhesives.—509—
Solution / coating grade
Supplied pre-dissolved for anticorrosion primers, tank linings and epoxy-ester/amine-cured paints.—50382 Shore D
Mineral / fused-silica filled potting compound
Use for electronic potting and tooling where low CTE, low shrinkage and better heat removal are required.—551.2—
Flame-retardant formulation
Required for electrical potting, cable joints and laminates that must meet UL 94 V-0 / GB fire codes.—58388 Shore D
NEATDefault
Neat / unfilled amine-cured casting
Baseline E-44 cured with an aliphatic/polyamide amine hardener — adhesives, primers, small castings.—624.585 Shore D
Anhydride-cured (MTHPA/MeHHPA) casting
Choose for electrical casting/potting where higher Tg, low dielectric loss and low colour are needed.—70388 Shore D
GFThis page
Glass-fibre reinforced laminate / FRP
Structural laminates, tanks, insulating boards — huge strength gain but anisotropic and abrasive to tooling.—3502—
Carbon-fibre reinforced laminate
For high specific stiffness and near-zero CTE structures; costly and electrically conductive (galvanic risk with Al).—9001.3—

What is E-44 GF?

E-44 GF is E-44 in the GF grade — structural laminates, tanks, insulating boards — huge strength gain but anisotropic and abrasive to tooling. E-44 GF has a tensile strength of 350 MPa (50.8 ksi), stronger than 100% of polymer grades. Elongation at break is 2% and the elastic modulus is 22 GPa (3.19 Msi). E-44 GF has a density of 1.9 g/cm³ (0.0686 lb/in³), heavier than 97% of polymer grades. Its glass-transition temperature is 105°C (221 °F). NEAT is the default condition FabDigit quotes; GF is available on request or by drawing note.

Advantages

  • Stiff — 22 GPa (3.19 Msi), better than 100% of polymer grades
  • Conducts heat well — 0.35 W/m·K (0.202 BTU/hr·ft·°F), better than 91% of polymer grades
  • Polishes to a fine finish — 70/100, better than 77% of polymer grades

Limitations

  • Heavy — 1.9 g/cm³ (0.0686 lb/in³), worse than 97% of polymer grades
  • Low fracture toughness — 0.6 MPa·√m (0.546 ksi·√in), worse than 96% of polymer grades
  • Limited ductility — 2%, worse than 95% of polymer grades
  • Difficult to machine — 35/100, worse than 84% of polymer grades
  • Degrades in UV without stabilisers — 25/100, worse than 76% of polymer grades

E-44 GF properties

Typical room-temperature values for E-44 GF; 13 are specific to this condition. Other listed values are E-44 reference data and may not represent this condition. Bars are the position among polymer grades.

Physical5

E-44 GF has a density of 1.9 g/cm³ (0.0686 lb/in³), heavier than 97% of polymer grades. Its glass-transition temperature is 105°C (221 °F).

Density1.9 g/cm³0.07 lb/in³
Glass Transition (Tg)105°C221 °F
Water Absorption (24 h)0.2%
Water Absorption (Saturation)2%
Refractive Index1.57

Mechanical15

E-44 GF has a tensile strength of 350 MPa (50.8 ksi), stronger than 100% of polymer grades. Elongation at break is 2% and the elastic modulus is 22 GPa (3.19 Msi).

Elastic (Young's) Modulus22 GPa3.2 Msi
Shear Modulus1.2 GPa0.17 Msi
Bulk Modulus4 GPa0.52 Msi
Poisson's Ratio0.35
Tensile Strength (Ultimate)350 MPa50.8 ksi
Elongation at Break2%
Compressive Strength330 MPa47.9 ksi
Compressive Modulus2.9 GPa0.42 Msi
Flexural Strength450 MPa65.3 ksi
Flexural Modulus21 GPa3 Msi
Shear Strength20 MPa2.9 ksi
Fracture Toughness (K_IC)0.6 MPa·√m0.55 ksi·√in
Izod Impact, Notched800 J/m15 ft·lbf/in
Hardness, Shore D85 Shore D
Hardness, Rockwell M100 HRM

Thermal10

E-44 GF is rated for continuous service to 120°C (248 °F). It conducts heat at 0.35 W/m·K (0.202 BTU/hr·ft·°F), better than 91% of polymer grades. Thermal expansion is 14 µm/m·K (7.78 µin/in·°F).

Thermal Conductivity0.35 W/m·K0.2 BTU/hr·ft·°F
Specific Heat Capacity1,050 J/kg·K0.25 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)14 µm/m·K7.8 µin/in·°F
Max Service Temperature (continuous)120°C248 °F
Min Service Temperature-50°C-58 °F
Heat Deflection Temp. @ 0.45 MPa115°C239 °F
Heat Deflection Temp. @ 1.8 MPa130°C266 °F
Flammability (UL 94)HB (unmodified casting; V-0 only with flame-retardant formulation)
Limiting Oxygen Index20%
Max Service Temperature (short-term)140°C284 °F

Electrical7

E-44 GF is an electrical insulator with a dielectric strength of 18 kV/mm (457.2 V/mil) and a resistivity of 1×10¹³ Ω·m.

Electrical Resistivity1×10¹³ Ω·m3.94×10²⁰ µΩ·in
Dielectric Strength18 kV/mm457 V/mil
Dielectric Constant (1 MHz)3.8
Dissipation Factor (1 MHz)0.02
Volume Resistivity1×10¹⁵ Ω·cm
Surface Resistivity1×10¹⁴ Ω
Comparative Tracking Index (CTI)350 V

Chemical & Environmental3

Corrosion resistance is excellent (85/100), better than 65% of polymer grades. UV resistance is poor.

Corrosion ResistanceExcellent85/100
UV / Weathering ResistancePoor25/100
Chemical Resistance SummaryVery good against water, dilute acids/alkalis, salt solutions, fuels, aliphatic solvents and most oils; attacked by concentrated oxidising acids, hot strong alkali, ketones, chlorinated solvents and amines; poor UV/weathering (chalking).

Sustainability4

Producing a kilogram of E-44 GF takes about 137 MJ of energy and emits 6.5 kg of CO₂ — more than 80% of polymer grades. Typical recycled content is 0%.

Embodied Energy (primary production)137 MJ/kg58,899 BTU/lb
Embodied Carbon (primary production)6.5 kg CO₂/kg
Embodied Water250 L/kg30 gal/lb
Typical Recycled Content0%

Manufacturability4

E-44 GF's machinability is fair (35/100, worse than 84% of polymer grades).

MachinabilityFair35/100
PolishabilityVery good70/100
Mold Shrinkage1.5%
Mold Temperature (typ.)80°C176 °F

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with E-44 GF

Is E-44 easy to machine?

Cured castings drill/turn/mill with sharp carbide, low feed and good chip clearance; keep tools cool to avoid softening near Tg, and use dust extraction for filled or fibre-reinforced versions.

Can E-44 be welded?

Thermoset — cannot be welded or remelted; joints are made by adhesive bonding with fresh resin or mechanical fastening.

Can E-44 be formed, bent or molded?

Mix with amine/polyamide (RT–80 °C) or anhydride (120–150 °C) hardener at the stoichiometric ratio; degas under vacuum for potting, control exotherm in thick sections (<25 mm per pour) and post-cure to develop full Tg.

What surface finishes work on E-44?

Sand and solvent-wipe before overcoating; cured epoxy takes paint and primers well but needs a PU or acrylic topcoat outdoors because it chalks under UV.

E-44 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.

ElementSpec limit (wt %)Nominal
epoxide value (eq/100 g)GB/T 13657 spec window; grade name derives from 0.440.41 – 0.470.44
volatilesGB/T 13657 limit, wt%≤ 2—
inorganic chlorine≤0.001 mol/100 g, expressed approx. as wt%≤ 0.04—
saponifiable (hydrolysable) chlorine≤0.02 mol/100 g, expressed approx. as wt%≤ 0.7—
bisphenol-A diglycidyl ether (DGEBA) oliepoxy value 0.41–0.47 eq/100 g, EEW about 213–244 g/eqbalance—

E-44 GF — frequently asked

What is E-44 GF used for?

E-44 GF is typically used for structural adhesives, protective coatings, composite matrix resin and tooling compounds. In short: chemical-resistant epoxy grade; adhesive and coating workhorse; higher crosslink density.

What is the tensile strength of E-44 GF?

E-44 GF has a typical tensile strength of 350 MPa (50.8 ksi) — stronger than 100% of polymer grades. Strength varies by condition: see the 9 listed tempers.

Is E-44 GF easy to machine?

Not especially — machinability is rated fair (35/100, worse than 84% of polymer grades). Cured castings drill/turn/mill with sharp carbide, low feed and good chip clearance; keep tools cool to avoid softening near Tg, and use dust extraction for filled or fibre-reinforced versions.

Can E-44 GF be welded?

Thermoset — cannot be welded or remelted; joints are made by adhesive bonding with fresh resin or mechanical fastening.

What surface finishes work on E-44 GF?

Sand and solvent-wipe before overcoating; cured epoxy takes paint and primers well but needs a PU or acrylic topcoat outdoors because it chalks under UV.

Can E-44 GF be formed, bent or molded?

Mix with amine/polyamide (RT–80 °C) or anhydride (120–150 °C) hardener at the stoichiometric ratio; degas under vacuum for potting, control exotherm in thick sections (<25 mm per pour) and post-cure to develop full Tg.

What is the maximum service temperature of E-44 GF?

E-44 GF is rated for continuous use to about 120°C (248 °F), and briefly to 140°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

Sources

  1. ASM Engineered Materials Handbook Vol. 3: Adhesives and Sealants / Vol. 2: Engineering Plastics — ASM International (1990)

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.