X8R
X8R is an extended-temperature Class II BaTiO₃ multilayer dielectric that holds its EIA capacitance tolerance up to +150 °C, offered in base-metal (BME), precious-metal (PME) and high-voltage (HV) formulations.
Reference datasheet — X8R 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.
Values for the BME condition
X8R tempers and conditions
X8R is supplied in 3 conditions, soft to hard. BME is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Precious-metal (Ag/Pd) electrode formulation, air fired | Choose for low-volume, high-reliability or thick-film/hybrid builds where air firing and Ag/Pd electrodes are required. | 580 HV | — | |||
BMEDefault Base-metal (Ni) electrode formulation, reducing-atmosphere fired | Mainstream automotive X8R: rare-earth/Mg/Mn core–shell BaTiO3 co-fired with Ni electrodes; lowest cost per µF at 150 °C. | 600 HV | 3 W/m·K | |||
High-voltage / thick-layer X8R formulation | Fine-grain, lower-K variant for 500–1000 V automotive DC-link and OBC snubber capacitors where breakdown field and DC-bias stability dominate. | 620 HV | — |
What is X8R?
X8R is an extended-temperature Class II BaTiO₃ multilayer dielectric that holds its EIA capacitance tolerance up to +150 °C, offered in base-metal (BME), precious-metal (PME) and high-voltage (HV) formulations. Engineers specify it for automotive and under-hood MLCCs where the +125 °C ceiling of X7R is insufficient; typical forms are surface-mount chip capacitors and lead-frame or flexible-termination assemblies. Fired density is about 5.75 g/cm³ with thermal conductivity near 3 W/m·K, and the material cannot be machined after firing (machinability 5). X7R is the lower-cost alternative when 125 °C is enough. X8R has a density of 5.75 g/cm³ (0.208 lb/in³), heavier than 60% of ceramic grades. It melts at 1,610°C (2,930 °F). X8R has a tensile strength of 70 MPa (10.2 ksi), weaker than 60% of ceramic grades. The elastic modulus is 115 GPa (16.7 Msi).
What is X8R used for?
- automotive electronics
- under-hood MLCCs
- high-temperature power modules
Limitations
- Limited service temperature — 150°C (302 °F), worse than 90% of ceramic grades
- Low fracture toughness — 1 MPa·√m (0.91 ksi·√in), worse than 84% of ceramic grades
- Poor heat conductor — 3 W/m·K (1.73 BTU/hr·ft·°F), worse than 77% of ceramic grades
X8R properties
Typical room-temperature values for X8R-BME; bars are the position among ceramic grades.
Physical3
X8R has a density of 5.75 g/cm³ (0.208 lb/in³), heavier than 60% of ceramic grades. It melts at 1,610°C (2,930 °F).
Mechanical10
X8R has a tensile strength of 70 MPa (10.2 ksi), weaker than 60% of ceramic grades. The elastic modulus is 115 GPa (16.7 Msi).
Thermal5
X8R is rated for continuous service to 150°C (302 °F). It conducts heat at 3 W/m·K (1.73 BTU/hr·ft·°F), worse than 77% of ceramic grades. Thermal expansion is 10 µm/m·K (5.56 µin/in·°F).
Electrical5
X8R is an electrical insulator with a dielectric strength of 25 kV/mm (635 V/mil) and a resistivity of 1×10¹¹ Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (85/100), better than 69% of ceramic grades.
Sustainability4
Producing a kilogram of X8R takes about 65 MJ of energy and emits 5.5 kg of CO₂ — less than 74% of ceramic grades. Typical recycled content is 0%.
Manufacturability3
X8R's machinability is not recommended (5/100, worse than 59% of ceramic 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 ceramic family
Yield strength against density for every ceramic grade FabDigit runs. X8R is highlighted; hover a dot for its name, or open the interactive family chart.
Working with X8R
Is X8R easy to machine?
Green tape is punched/laser-cut; fired ceramic requires diamond grinding, dicing or lapping — no conventional machining.
Can X8R be welded?
Not weldable; joined by soldering/sintering to Ni-barrier + Sn-plated terminations, or by conductive epoxy for high-vibration automotive use.
Can X8R be formed, bent or molded?
Tape-cast to 1–20 µm layers, screen-printed Ni electrodes, stacked/laminated, binder burnout then co-fired ~1250–1300 °C in low-pO2 N2/H2 atmosphere; firing window is narrow and Ba/Ti ratio sensitive.
X8R 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 |
|---|---|---|
| Ho2O3/Dy2O3/Y2O3 (rare-earth shell formegrain-shell doping for reliability and TCC flattening | 0.8 – 4 | 2 |
| MgOacceptor dopant, grain-growth control | 0.3 – 2 | 1 |
| MnO/Mn3O4reduction-resistance in BME firing | 0.05 – 0.6 | 0.2 |
| Nb2O5Curie-point shifter for +150 °C stability (Nb–Co or Bi-based systems used) | 0.3 – 2.5 | 1.2 |
| SiO2 + BaO/CaO glass sintering aiddensification aid | 0.5 – 2.5 | 1.2 |
| CaZrO3/ZrO2optional, TCC and IR tuning | 0 – 2 | 0.8 |
| BaTiO3core–shell fine-grain base powder, Ba/Ti ≈ 1.000–1.005 | ≥ 85 (balance) |
What surface finishes work on X8R?
Terminations dipped and fired (Cu), then Ni/Sn barrier plating; flexible-termination or lead-frame options used to resist board-flex cracking in automotive assemblies.
How much does X8R cost?
X8R is a high-cost ceramic ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
X8R — frequently asked
What is X8R used for?
X8R is typically used for automotive electronics, under-hood MLCCs and high-temperature power modules. In short: 150 °C Class II dielectric; automotive under-hood MLCCs; wider range than X7R.
What is the tensile strength of X8R?
X8R has a typical tensile strength of 70 MPa (10.2 ksi) — weaker than 60% of ceramic grades. Strength varies by condition: see the 3 listed tempers.
Is X8R easy to machine?
Not especially — machinability is rated not recommended (5/100, worse than 59% of ceramic grades). Green tape is punched/laser-cut; fired ceramic requires diamond grinding, dicing or lapping — no conventional machining.
Can X8R be welded?
Not weldable; joined by soldering/sintering to Ni-barrier + Sn-plated terminations, or by conductive epoxy for high-vibration automotive use.
What surface finishes work on X8R?
Terminations dipped and fired (Cu), then Ni/Sn barrier plating; flexible-termination or lead-frame options used to resist board-flex cracking in automotive assemblies.
Can X8R be formed, bent or molded?
Tape-cast to 1–20 µm layers, screen-printed Ni electrodes, stacked/laminated, binder burnout then co-fired ~1250–1300 °C in low-pO2 N2/H2 atmosphere; firing window is narrow and Ba/Ti ratio sensitive.
What is the maximum service temperature of X8R?
X8R is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does X8R cost?
X8R is a high-cost ceramic ($$$$), pricier than about 78% 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
- EIA RS-198 / IEC 60384-21 Class II temperature-characteristic codes (X8R) — EIA / IEC (2019)
- AEC-Q200 Stress Test Qualification for Passive Components — Automotive Electronics Council (2023)
- ASM Engineered Materials Handbook Vol.4 — Ceramics and Glasses — ASM International (1991)
- Automotive X8R MLCC series datasheets (KEMET, TDK, Murata, AVX/Kyocera) — various (2024)
- BaTiO3 dielectric powder property data (Sakai Chemical / Fuji Titanium / technical bulletins) — 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.