Phenolic XX
ASTM D709 · also Garolite XX, Bakelite
Phenolic XX is a paper-base phenolic (PF) thermoset laminate to NEMA grade XX and ASTM D709, pressed from cellulose paper and phenol-formaldehyde resin.
Values for the Phenolic Matrix condition
Phenolic XX grades and fills
Phenolic XX is supplied in 6 conditions, soft to hard. Phenolic Matrix is the default FabDigit quotes; the values on this page are for it.
Compare all 6 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
NEMA XXXPC | Pick for high-volume cold blanking of thin insulation parts without pre-heating the sheet. | 76 | 1.6 | 87 Shore D | |
NEMA XXXP | Pick for thin sheet that must be blanked/punched (terminal strips, washers) while keeping good electrical loss figures. | 80 | 1.5 | 88 Shore D | |
NEMA XXX | Pick for radio-frequency or humid-environment insulation where low loss and low moisture pickup matter more than strength. | 83 | 1.4 | 89 Shore D | |
Flame-retardant paper phenolic | Pick where a UL 94 V-0 rating is mandated for the insulating part (appliance and switchgear insulation). | 85 | 1.4 | 90 Shore D | |
Phenolic MatrixDefault NEMA XX cellulose-paper / phenolic laminate (default) | General-purpose paper-phenolic sheet/rod/tube for combined mechanical and low-frequency electrical duty at low cost. | 90 | 1.5 | 90 Shore D | |
NEMA X | Pick when only mechanical strength matters (spacers, jigs, wear pads) and electrical performance is irrelevant. | 100 | 1.6 | 91 Shore D |
What is Phenolic XX?
Phenolic XX is a paper-base phenolic (PF) thermoset laminate to NEMA grade XX and ASTM D709, pressed from cellulose paper and phenol-formaldehyde resin. It is used for low-voltage electrical and mechanical parts in sheet, rod and tube because it punches and machines easily (machinability 80) and costs less than glass-epoxy laminates, with 90 MPa tensile strength and about 120 °C service temperature. Moisture pickup is higher and strength lower than epoxy-glass grades, so use XXXP/XXXPC for better electrical performance, canvas-base C/CE for mechanical duty, or G10/FR-4 where strength and humidity resistance govern. Phenolic XX has a density of 1.34 g/cm³ (0.0484 lb/in³), lighter than 78% of composite grades. Its glass-transition temperature is 170°C (338 °F). Phenolic XX 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 7 GPa (1.02 Msi).
What is Phenolic XX used for?
- Electrical insulators and barriers
- Terminal boards and tag strips
- Punched washers, gaskets and shims
- Coil and transformer spacers
- Switch and relay bases
- Low-load bushings and cams
- Fixture and jig wear pads
Advantages
- Easy to machine — 80/100, better than 85% of composite grades
- Low embodied carbon — 4.5 kg CO₂/kg, better than 79% of composite grades
- Lightweight — 1.34 g/cm³ (0.0484 lb/in³), better than 78% of composite grades
Limitations
- Degrades in UV without stabilisers — 25/100, worse than 86% of composite grades
- Limited service temperature — 120°C (248 °F), worse than 78% of composite grades
- Low stiffness — 7 GPa (1.02 Msi), worse than 77% of composite grades
- Poor heat conductor — 0.25 W/m·K (0.144 BTU/hr·ft·°F), worse than 76% of composite grades
- Absorbs moisture — dry before molding — 1.3%, worse than 75% of composite grades
Phenolic XX properties
Typical room-temperature values for Phenolic XX-Phenolic Matrix; bars are the position among composite grades.
Physical4
Phenolic XX has a density of 1.34 g/cm³ (0.0484 lb/in³), lighter than 78% of composite grades. Its glass-transition temperature is 170°C (338 °F).
Mechanical14
Phenolic XX 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 7 GPa (1.02 Msi).
Thermal10
Phenolic XX 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
Phenolic XX is an electrical insulator with a dielectric strength of 15 kV/mm (381 V/mil) and a resistivity of 1×10⁹ Ω·m.
Chemical & Environmental3
Corrosion resistance is good (65/100), worse than 72% of composite grades. UV resistance is poor.
Sustainability3
Producing a kilogram of Phenolic XX takes about 80 MJ of energy and emits 4.5 kg of CO₂ — less than 84% of composite grades. Typical recycled content is 5%.
Manufacturability4
Phenolic XX's machinability is very good (80/100, better than 85% of composite grades); weldability not recommended (0/100); formability poor (15/100).
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. Phenolic XX is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Phenolic XX
Is Phenolic XX easy to machine?
Cuts, drills and turns easily with sharp carbide tooling at high speed and no coolant; dust is abrasive and irritating, so use vacuum extraction and back up holes to avoid edge chipping and delamination.
Can Phenolic XX be welded?
Thermoset — cannot be welded or thermally reformed; join by bolting, riveting or epoxy/phenolic adhesive bonding after abrading the surface.
Can Phenolic XX be formed, bent or molded?
Supplied as fully cured sheet, rod and tube; thin sheet (P/PC grades) can be hot- or cold-punched, but thick stock must be machined to shape.
Manufacturability
The process limits FabDigit's quote engine applies to Phenolic XX. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Better80 / 100 |
|---|---|
| Cutting speed (rough / finish) | — / — |
| Minimum wall | — |
| Minimum internal radius | — |
| Drill depth limit | |
| Best surface (machined / polished) | Ra — / — |
| Hardenable after machining | — |
Sheet metal
| Formability | Not Recommend15 / 100 |
|---|---|
| Weldability | Not Recommend0 / 100 |
Phenolic XX 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 resinresole/novolac, fully cured thermoset binder | 40 – 55 | 48 |
| volatiles/residual moisture | 0 – 2 | 1 |
| cellulose kraft paperreinforcement web, multiple plies | ≥ 45 (balance) |
What surface finishes work on Phenolic XX?
Sand or scrape edges to remove fuzz and seal machined surfaces with varnish/epoxy to limit moisture pickup; the natural finish is brown-to-black and not platable, though it accepts primer-based paint.
Surface treatments FabDigit runs on composite parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Equivalent designations
Standards and trade names that resolve to Phenolic XX in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- D709
- Trade names
- Garolite XXBakelite
- Also called
- NEMA XX
How much does Phenolic XX cost?
Phenolic XX is a premium-cost composite ($$$), pricier than about 58% 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.
Phenolic XX — frequently asked
What is Phenolic XX used for?
Phenolic XX is typically used for electrical insulators and barriers, terminal boards and tag strips, punched washers, gaskets and shims, coil and transformer spacers, switch and relay bases and low-load bushings and cams. In short: classic phenolic laminate.
What is the tensile strength of Phenolic XX?
Phenolic XX has a typical tensile strength of 90 MPa (13.1 ksi) — weaker than 72% of composite grades. Strength varies by condition: see the 6 listed tempers.
Is Phenolic XX easy to machine?
Yes — machinability is rated very good (80/100, better than 85% of composite grades). Cuts, drills and turns easily with sharp carbide tooling at high speed and no coolant; dust is abrasive and irritating, so use vacuum extraction and back up holes to avoid edge chipping and delamination.
Can Phenolic XX be welded?
Not readily — weldability is rated not recommended (0/100). Thermoset — cannot be welded or thermally reformed; join by bolting, riveting or epoxy/phenolic adhesive bonding after abrading the surface.
What surface finishes work on Phenolic XX?
Sand or scrape edges to remove fuzz and seal machined surfaces with varnish/epoxy to limit moisture pickup; the natural finish is brown-to-black and not platable, though it accepts primer-based paint.
Can Phenolic XX be formed, bent or molded?
Supplied as fully cured sheet, rod and tube; thin sheet (P/PC grades) can be hot- or cold-punched, but thick stock must be machined to shape.
What is the maximum service temperature of Phenolic XX?
Phenolic XX 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 Phenolic XX cost?
Phenolic XX is a premium-cost composite ($$$), pricier than about 58% 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.
Can FabDigit make parts in Phenolic XX?
Yes — Phenolic XX is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- NEMA LI 1 — Industrial Laminating Thermosetting Products — NEMA (1998)
- ASTM D709 — Standard Specification for Laminated Thermosetting Materials — ASTM (2017)
- Paper-phenolic industrial laminate grades X / XX / XXX / XXXP — Norplex-Micarta (2022)
- Engineered Materials Handbook Vol. 2 — Engineering Plastics (phenolic laminates) — ASM International (1988)
- MatWeb paper-reinforced phenolic laminate property listings — MatWeb (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.