Polyester Film Capacitors & Mylar Assortments
Polyester film capacitors and Mylar component kits
Polyester film capacitors use a polyester dielectric, commonly described as Mylar, MKT or metallized polyester. This collection centers on through-hole individual values and multi-value assortments for prototyping, repair and signal-circuit selection. Listings range from small pF and nF values to selected µF options; each variant determines its own capacitance, tolerance, working voltage, package and quantity. Several listings mix other film dielectrics, AC safety parts or even non-film items, so the product and variant specification takes priority over the collection name.
What you can compare here
- Individual polyester parts: Mylar and metallized polyester radial parts commonly appear with 2A (100 V), 2E (250 V), 2G (400 V), 2J (630 V) and selected 3A (1000 V) value codes in listings. Verify the actual variant's code, voltage and tolerance rather than applying any one rating to the whole product.
- Axial MKT parts: an axial metallized polyester listing offers multiple capacitance and voltage options for crossover construction. Check end-to-end mounting clearance, lead style and circuit requirements rather than treating axial and radial formats as drop-in equivalents.
- Assortment boxes and packs: 14-, 15-, 18-, 24- and other multi-value descriptions occur, with different numbers of pieces, value ranges, voltages and packaging. Count values and pieces per value on the selected offer; a headline total is not an electrical specification.
- Other constructions within the same collection: CBB22 and other polypropylene film options, X2/X1/Y1/Y2-labeled safety items, one high-voltage ceramic assortment and passive audio crossover network listings are not ordinary standalone polyester film capacitors. Some WIMA, NISSEI and other brand claims in titles do not independently establish manufacturer provenance.
How to choose a polyester capacitor
- Match the circuit's required capacitance and convert units carefully: 100 nF equals 0.1 µF, while 1 nF equals 1000 pF. A three-digit code such as 104 commonly represents 100 nF, but verify the component's own marking and listing.
- Read the selected variant's DC or AC working-voltage rating, and allow for the actual circuit voltage and applicable design margin. A DC marking does not establish an AC mains rating.
- Check tolerance, dielectric and construction. Polyester and polypropylene can differ in losses, temperature behavior and pulse suitability despite matching capacitance.
- Compare lead pitch, axial versus radial orientation, body dimensions and temperature rating against the PCB and enclosure.
- For pulse, ripple or high-frequency service, check the specific datasheet for dissipation factor, ESR, dv/dt and current limits rather than inferring them from a nominal voltage or CBB code.
- For a kit, confirm the complete value list, voltage for each value and the number of parts included.
Safety and application boundaries
Do not use a general-purpose 100 V, 400 V or 630 V DC polyester capacitor directly across AC mains simply because its nominal voltage looks high. Across-the-line X capacitors and line-to-earth Y capacitors require the correct verified safety class and approvals for the exact circuit location. A product title mentioning X2, Y2 or 275 VAC alone is not proof of approval. Likewise, an audio crossover module includes an assembled network rather than just a replaceable loose capacitor; match its schematic, driver impedance and power limits before use.
Buying checklist
- Exact capacitance, code, tolerance and dielectric
- Selected variant's DC or AC rating and temperature range
- Radial or axial leads, pitch and body dimensions
- Pulse/ripple data or independently verified safety class when needed
- Single-value pack versus assortment, quantity and values per pack
Frequently asked questions
Is a 2A104J the same as any 104 capacitor?
No. The 104 code commonly denotes 100 nF, but the complete part designation, tolerance, dielectric, voltage and physical size must also match.
Can polyester replace polypropylene in a snubber or crossover?
Not automatically. Compare the required loss, pulse, temperature, voltage and circuit conditions with the exact part specifications.
Does 630 V DC make a polyester capacitor X2-rated?
No. Mains suppression needs a verified X-class component appropriate to the location and applicable approvals.
Are all products here polyester capacitors?
No. Some listings contain polypropylene or safety-class options, ceramic kits or a complete crossover network. Check the selected product and variant before ordering.
