XXP FR
Flame-retardant grade
ASTM D709 Grade XXP, D709 Type XXP
FR = flame-retardant paper-phenolic
Pick when a UL 94 V-0 rating is mandatory in appliance or consumer-electronics enclosures; slightly lower punchability and impact than natural XXP.
Values for the FR condition
Other XXP grades and fills
XXP is listed in 2 conditions; see the grade overview at XXP.
- FR
- HP
Compare all 2 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
FRThis page Flame-retardant paper-phenolic | Pick when a UL 94 V-0 rating is mandatory in appliance or consumer-electronics enclosures; slightly lower punchability and impact than natural XXP. | — | 76 | 1.1 | 102 HRM |
Hot-punch stock | Same laminate specified for thicker sections (>1.6 mm) that must be warmed before punching to avoid edge cracking and delamination. | — | 80 | 1.3 | 100 HRM |
What is XXP FR?
XXP FR is XXP in the FR grade — pick when a UL 94 V-0 rating is mandatory in appliance or consumer-electronics enclosures; slightly lower punchability and impact than natural XXP. XXP FR has a tensile strength of 76 MPa (11 ksi), weaker than 78% of composite grades. The elastic modulus is 7.5 GPa (1.09 Msi). XXP FR has a density of 1.4 g/cm³ (0.0506 lb/in³), lighter than 64% of composite grades. Its glass-transition temperature is 155°C (311 °F).
Advantages
- Low embodied carbon — 3.2 kg CO₂/kg, better than 95% of composite grades
- Easy to machine — 70/100, better than 77% of composite grades
Limitations
- Needs corrosion protection — 55/100, worse than 87% of composite grades
- Limited service temperature — 115°C (239 °F), worse than 84% of composite grades
- Hard to polish — 25/100, worse than 76% of composite grades
XXP FR properties
Typical room-temperature values for XXP FR; 20 are specific to this condition. Other listed values are XXP reference data and may not represent this condition. Bars are the position among composite grades.
Physical4
XXP FR has a density of 1.4 g/cm³ (0.0506 lb/in³), lighter than 64% of composite grades. Its glass-transition temperature is 155°C (311 °F).
Mechanical10
XXP FR has a tensile strength of 76 MPa (11 ksi), weaker than 78% of composite grades. The elastic modulus is 7.5 GPa (1.09 Msi).
Thermal8
XXP FR is rated for continuous service to 115°C (239 °F). It conducts heat at 0.26 W/m·K (0.15 BTU/hr·ft·°F), worse than 71% of composite grades. Thermal expansion is 25 µm/m·K (13.9 µin/in·°F).
Electrical7
XXP FR is an electrical insulator with a dielectric strength of 19 kV/mm (482.6 V/mil) and a resistivity of 5×10⁸ Ω·m.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 87% of composite grades. UV resistance is poor.
Sustainability4
Producing a kilogram of XXP FR takes about 62 MJ of energy and emits 3.2 kg of CO₂ — less than 95% of composite grades. Typical recycled content is 0%.
Manufacturability2
XXP FR's machinability is very good (70/100, better than 77% of composite grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with XXP FR
Is XXP easy to machine?
Drills, saws and turns easily with carbide tooling and high rake; dust is abrasive and irritating, so vacuum extraction is required and coolant is avoided to keep the paper core dry.
Can XXP be welded?
Not weldable — thermoset laminate; join by bonding (epoxy), riveting or mechanical fastening.
Can XXP be formed, bent or molded?
Supplied as pressed flat sheet; it is not thermoformable but is designed to be blanked/punched cold in thin gauges and at 60–110 °C above roughly 1.6 mm.
What surface finishes work on XXP?
Edges should be deburred and sealed (varnish or epoxy) to limit moisture wicking; surface can be silk-screened or varnished but not plated or anodized.
XXP 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 (phenolic) resinresole/novolac binder, moisture-resistant modified type for XXP | 38 – 52 | 45 |
| cellulose kraft paperimpregnated paper web substrate | ≥ 48 (balance) | — |
XXP FR — frequently asked
What is XXP FR used for?
XXP FR is typically used for precision punched insulators, terminal boards and relay bases. In short: punching-grade paper phenolic; better moisture resistance than XX; high-volume blanked insulation.
What is the tensile strength of XXP FR?
XXP FR has a typical tensile strength of 76 MPa (11 ksi) — weaker than 78% of composite grades. Strength varies by condition: see the 2 listed tempers.
Is XXP FR easy to machine?
Yes — machinability is rated very good (70/100, better than 77% of composite grades). Drills, saws and turns easily with carbide tooling and high rake; dust is abrasive and irritating, so vacuum extraction is required and coolant is avoided to keep the paper core dry.
Can XXP FR be welded?
Not weldable — thermoset laminate; join by bonding (epoxy), riveting or mechanical fastening.
What surface finishes work on XXP FR?
Edges should be deburred and sealed (varnish or epoxy) to limit moisture wicking; surface can be silk-screened or varnished but not plated or anodized.
Can XXP FR be formed, bent or molded?
Supplied as pressed flat sheet; it is not thermoformable but is designed to be blanked/punched cold in thin gauges and at 60–110 °C above roughly 1.6 mm.
What is the maximum service temperature of XXP FR?
XXP FR is rated for continuous use to about 115°C (239 °F), and briefly to 155°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM D709 — Standard Specification for Laminated Thermosetting Materials — ASTM International (2017)
- NEMA LI 1 — Industrial Laminated Thermosetting Products — NEMA (1998)
- Paper-phenolic industrial laminate (XX/XXP/XXX/XXXP) datasheets — industrial laminate producers (2023)
- Engineered Materials Handbook, Vol. 2: Engineering Plastics — ASM International (1988)
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.