Phenolic XX X (NEMA X)
Hardness band
ASTM D709 · also Garolite XX, Bakelite
Pick when only mechanical strength matters (spacers, jigs, wear pads) and electrical performance is irrelevant.
Values for the X condition
Other Phenolic XX grades and fills
Phenolic XX is listed in 6 conditions; see the grade overview at Phenolic XX.
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 |
XThis page 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 X?
Phenolic XX X is Phenolic XX heat treated to X — pick when only mechanical strength matters (spacers, jigs, wear pads) and electrical performance is irrelevant. Phenolic XX X has a tensile strength of 100 MPa (14.5 ksi), weaker than 67% of composite grades. Elongation at break is 1.6% and the elastic modulus is 8 GPa (1.16 Msi). Phenolic XX X 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 Matrix is the default condition FabDigit quotes; X is available on request or by drawing note.
Advantages
- Forms and bends easily — 20/100, better than 100% of composite grades
- 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
- Absorbs moisture — dry before molding — 2%, worse than 88% of composite grades
- Degrades in UV without stabilisers — 25/100, worse than 86% 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
Phenolic XX X properties
Typical room-temperature values for Phenolic XX X; 24 are specific to this condition. Other listed values are Phenolic XX reference data and may not represent this condition. Bars are the position among composite grades.
Physical4
Phenolic XX X 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 X has a tensile strength of 100 MPa (14.5 ksi), weaker than 67% of composite grades. Elongation at break is 1.6% and the elastic modulus is 8 GPa (1.16 Msi).
Thermal10
Phenolic XX X is rated for continuous service to 120°C (248 °F). It conducts heat at 0.27 W/m·K (0.156 BTU/hr·ft·°F), worse than 71% of composite grades. Thermal expansion is 25 µm/m·K (13.9 µin/in·°F).
Electrical7
Phenolic XX X is an electrical insulator with a dielectric strength of 10 kV/mm (254 V/mil) and a resistivity of 1×10⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 79% of composite grades. UV resistance is poor.
Sustainability3
Producing a kilogram of Phenolic XX X 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 X's machinability is very good (80/100, better than 85% of composite grades); weldability not recommended (0/100); formability poor (20/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Phenolic XX X
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.
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.
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) | — |
Phenolic XX X — frequently asked
What is Phenolic XX X used for?
Phenolic XX X 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 X?
Phenolic XX X has a typical tensile strength of 100 MPa (14.5 ksi) — weaker than 67% of composite grades. Strength varies by condition: see the 6 listed tempers.
Is Phenolic XX X 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 X 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 X?
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 X 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 X?
Phenolic XX X 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.
Can FabDigit make parts in Phenolic XX X?
Yes — Phenolic XX X 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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.