3021
3021 is a woven E-glass/epoxy thermoset laminate rated for a higher thermal class than the basic 3240 epoxy-glass grade, comparable in service to NEMA G-11 (ASTM D709 Grade G-11).
Reference datasheet — 3021 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.
3021 grades and fills
3021 is supplied in one standard condition, FR.
Supply forms, finishes and certifications
Ways 3021 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
CCL | Copper-clad paper-phenolic base | Coating |
STDDefault | Standard 3021 phenolic paper laminate | Standard supply |
What is 3021?
3021 is a woven E-glass/epoxy thermoset laminate rated for a higher thermal class than the basic 3240 epoxy-glass grade, comparable in service to NEMA G-11 (ASTM D709 Grade G-11). It is used for structural electrical insulation that must hold dielectric strength and stiffness to 120 °C, and is supplied as sheet in standard, flame-retardant (FR) and copper-clad (CCL) forms. Unlike G-10/FR-4 it is a hot-punching grade, so thin sheet can be blanked rather than routed. It cannot be welded or thermoformed, and machined edges need sealing against moisture; G-10/FR-4 is cheaper where 120 °C capability is not required. 3021 has a density of 1.4 g/cm³ (0.0506 lb/in³), lighter than 64% of composite grades. Its glass-transition temperature is 150°C (302 °F). 3021 has a tensile strength of 90 MPa (13.1 ksi), weaker than 72% of composite grades. Elongation at break is 1.5% and the elastic modulus is 8 GPa (1.16 Msi).
What is 3021 used for?
- elevated-temperature electrical insulation
- transformer and motor insulation parts
- structural supports
Advantages
- Low embodied carbon — 3 kg CO₂/kg, better than 96% of composite grades
- Easy to machine — 80/100, better than 85% of composite grades
Limitations
- Absorbs moisture — dry before molding — 1.5%, worse than 81% of composite grades
- Needs corrosion protection — 60/100, worse than 79% of composite grades
- Limited service temperature — 120°C (248 °F), worse than 78% of composite grades
- Poor heat conductor — 0.25 W/m·K (0.144 BTU/hr·ft·°F), worse than 76% of composite grades
3021 properties
Typical room-temperature values; bars are the position among composite grades.
Physical4
3021 has a density of 1.4 g/cm³ (0.0506 lb/in³), lighter than 64% of composite grades. Its glass-transition temperature is 150°C (302 °F).
Mechanical9
3021 has a tensile strength of 90 MPa (13.1 ksi), weaker than 72% of composite grades. Elongation at break is 1.5% and the elastic modulus is 8 GPa (1.16 Msi).
Thermal9
3021 is rated for continuous service to 120°C (248 °F). It conducts heat at 0.25 W/m·K (0.144 BTU/hr·ft·°F), worse than 76% of composite grades. Thermal expansion is 25 µm/m·K (13.9 µin/in·°F).
Electrical7
3021 is an electrical insulator with a dielectric strength of 12 kV/mm (304.8 V/mil) and a resistivity of 1×10⁹ Ω·m.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 79% of composite grades. UV resistance is fair.
Sustainability2
Producing a kilogram of 3021 takes about 55 MJ of energy and emits 3 kg of CO₂ — less than 97% of composite grades.
Manufacturability2
3021's machinability is very good (80/100, better than 85% of composite 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 composite family
Yield strength against density for every composite grade FabDigit runs. 3021 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 3021
Is 3021 easy to machine?
Machines like a hard thermoset — carbide or PCD tools, high speed/low feed, back it up when drilling to stop exit delamination, and extract the abrasive paper-phenolic dust.
Can 3021 be welded?
Thermoset: cannot be welded; join by bolting, riveting, or epoxy/phenolic adhesive after abrading the surface.
Can 3021 be formed, bent or molded?
Not thermoformable; 3021 is specifically the hot-punching grade — punch sheets ≤3 mm after preheating to ~90–120 °C for clean, crack-free blanks.
3021 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 |
|---|---|---|
| phenol-formaldehyde (resole) resinimpregnating matrix, may contain drying-oil or FR modifiers | 40 – 55 | 47 |
| pigment / filleriron-oxide (orange-red) or carbon black | 0 – 3 | 1 |
| cellulose kraft paperreinforcement plies; NOT glass fabric | ≥ 45 (balance) |
What surface finishes work on 3021?
Edges sand and deburr easily; seal cut edges with varnish or epoxy to limit moisture pickup, and expect no plating or anodising (paint/varnish only).
How much does 3021 cost?
3021 is a standard-cost composite ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
3021 — frequently asked
What is 3021 used for?
3021 is typically used for elevated-temperature electrical insulation, transformer and motor insulation parts and structural supports. In short: hot-punchable epoxy laminate; G-11 thermal class; 120 °C insulation grade.
What is the tensile strength of 3021?
3021 has a typical tensile strength of 90 MPa (13.1 ksi) — weaker than 72% of composite grades.
Is 3021 easy to machine?
Yes — machinability is rated very good (80/100, better than 85% of composite grades). Machines like a hard thermoset — carbide or PCD tools, high speed/low feed, back it up when drilling to stop exit delamination, and extract the abrasive paper-phenolic dust.
Can 3021 be welded?
Thermoset: cannot be welded; join by bolting, riveting, or epoxy/phenolic adhesive after abrading the surface.
What surface finishes work on 3021?
Edges sand and deburr easily; seal cut edges with varnish or epoxy to limit moisture pickup, and expect no plating or anodising (paint/varnish only).
Can 3021 be formed, bent or molded?
Not thermoformable; 3021 is specifically the hot-punching grade — punch sheets ≤3 mm after preheating to ~90–120 °C for clean, crack-free blanks.
What is the maximum service temperature of 3021?
3021 is rated for continuous use to about 120°C (248 °F), and briefly to 150°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 3021 cost?
3021 is a standard-cost composite ($$), cheaper than about 71% 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
- IEC 60893-3-4 Industrial rigid laminated sheets — Phenolic resin sheets (PF CP) — IEC (2013)
- ASTM D709 Standard Specification for Laminated Thermosetting Materials — ASTM (2017)
- Engineered Materials Handbook Vol. 2 — Engineering Plastics (laminates section) — ASM International (1988)
- Paper-phenolic laminate (3021/XX/XPC) sheet datasheets — Chinese insulation-board producers ( / ) (2024)
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.