Each form serves a different dielectric or mechanical demand
High mechanical strength for structural insulation
Bendable for wraps, coils and complex shapes
Compressible for gaskets & sealing
Asbestos-free insulating board
Mica sheet is a flat insulating material made from natural mica mineral, either Muscovite or Phlogopite, bonded with a heat-resistant resin or sintered without binder. Its layered crystalline structure gives mica outstanding dielectric strength (15–25 kV/mm), thermal stability up to 900°C for Phlogopite, near-zero moisture absorption and full chemical inertness. These properties make mica sheet the standard material for electrical insulation in motors, generators and transformers, for thermal barriers in industrial furnaces, and for gaskets in high-temperature sealing applications.
As an experienced mica sheet manufacturer in China, Kaxite Sealing supplies Muscovite and Phlogopite mica in rigid, flexible, soft and hard forms, in standard sizes 1000 × 1200 mm and 1000 × 2400 mm, cut to any shape including RECTANGULAR, OVAL and CIRCULAR (ROUND). Related mica products: Mica Gaskets, Mica Tapes and Mica Tubes.
Choose by service temperature and application
The most common mica type. Excellent dielectric strength and low dielectric loss. Preferred for electrical insulation in motors, generators and transformers.
Higher temperature stability than Muscovite. Preferred for high-heat thermal insulation in furnaces, kilns, and industrial equipment up to 900°C.
How Muscovite and Phlogopite compare against alternative insulating materials
Mica maintains its dielectric strength at temperatures where fiberglass, phenolic and most plastics fail. This is why mica sheet is the standard high-temperature insulating material for electric motors, generators and industrial furnaces.
| Parameter | Muscovite | Phlogopite |
|---|---|---|
| Sheet Forms | Rigid / Flexible / Soft | Rigid / Flexible / Hard |
| Standard Sizes | 1000 × 1200 / 2400 mm | 1000 × 1200 / 2400 mm |
| Thickness Range | 0.1 mm and up (custom) | 0.1 mm and up (custom) |
| Max Temperature | 500°C | 900°C |
| Dielectric Strength | 15 – 25 kV/mm | 15 – 20 kV/mm |
| Density | 2.6 – 2.9 g/cm³ | 2.8 – 3.2 g/cm³ |
| Water Absorption | < 0.1% | < 0.1% |
| Shape Options | Rectangular / Oval / Circular — cut to any drawing | |
Custom sizes and thicknesses available on request. For full specifications, please review our Our Quality page or send us your inquiry.
Wherever high-temperature insulation and dielectric strength are required
Slot insulation & commutator segments
Dielectric barriers & coil insulation
Thermal barriers & window glass
Heating element supports & insulation
High-temperature flange sealing
Thermal protection & dielectric layers
Spatter shields & thermal barriers
PCB substrates & heat spreaders
Choose Muscovite for electrical insulation up to 500°C — it has the best dielectric strength and lowest dielectric loss, making it ideal for motors, generators and transformers. Choose Phlogopite when service temperature exceeds 500°C, up to 900°C — it is preferred for industrial furnaces, kilns and high-heat thermal barriers. Contact us with your service conditions for a recommendation.
Rigid sheet has high mechanical strength for structural insulation. Flexible sheet bends easily for wrapping coils and complex shapes. Soft sheet is compressible for gasket and sealing applications. Hard sheet is a dense asbestos-free insulating board for electromechanical applications. See our Soft Mica Sheets and Hard Mica Sheet product pages.
Yes. We cut to any shape — RECTANGULAR, OVAL, CIRCULAR (ROUND) — and any thickness to your drawing. Standard stock sizes are 1000 × 1200 mm and 1000 × 2400 mm. Please send your inquiry with a sketch for a fast quotation.
No. Mica sheet has a water absorption rate below 0.1%, keeping its dielectric strength stable in humid or wet environments. This makes it far more reliable than fiberglass or phenolic sheet in tropical or marine installations.
Yes. Every shipment includes Mill Test Certificate, dimensional inspection record and material composition report. RoHS and REACH documentation are available on request. See our Our Certificate page.
MOQ is 10 pcs (or 10 sheets) for standard sizes. Lead time is 7-15 days after order confirmation. Payment terms are T/T or L/C. Free samples are available — you only cover the courier cost. Contact Us to discuss.
Send us your drawing or dimensions — we CNC-cut mica sheet to any shape (rectangular, oval, circular) or complex geometry at no extra tooling charge.
Get Custom QuoteVerify material composition, thickness and dielectric strength against your own spec before placing a bulk order. Both Muscovite and Phlogopite samples available.
Contact Us NowMica sheet (also called mica board or micanite sheet) is a flat insulation product made from muscovite or phlogopite mica paper bonded with resin, available in both rigid and flexible forms. The plate-like crystal structure of the mica mineral gives the sheet superior electrical insulation, thermal insulation and chemical resistance — properties that make it the standard choice where heat meets electrical current. Kaxite supplies mica sheet in two rigid grades: MR SSP with heat resistance to 1200 °C and MR SSM to 1000 °C. Standard sizes are 1000 × 1200 mm and 1000 × 2400 mm; thickness ranges from 0.1 mm up to 101.6 mm. Applications include heating elements, induction / arc / high-frequency furnaces, high-voltage insulation and industrial gasket industries.
Soft mica sheet (also called flexible mica sheet or soft micanite sheet) is a compressible sealing material made by mixing mica material with a proper adhesive, then pressing and baking the compound into a flat sheet. It is soft and heat-resistant under normal conditions and delivers the best and most reliable permanent sealing characteristics. Soft mica sheet is used wherever a low minimum compression load is required — cutting into various gaskets, acting as filler for spiral wound gaskets, and forming a compensating seal in ceramic and steel joints that have unequal thermal expansion. Kaxite supplies soft mica sheet, model KXT-B501, in standard sizes 1000 × 1200 mm and 600 × 1000 mm, thickness 0.5–5.0 mm, with temperature resistance 650–900 °C, pressure capability up to 10 MPa and density 1.8–2.1 g/cm³.
Hard mica sheet (also called mica insulation board or asbestos-free mica board) is a rigid, high-performance insulation material made from mica paper bonded with 10–15% resin binder and pressed into dense sheet form. It is designed as a direct replacement for asbestos and other insulating boards in metallurgy, chemical engineering, electric heaters and electromechanical applications. The board combines high mechanical strength with good heat resistance, delivers a dielectric strength of 25 kV/mm at 20 °C (13 kV/mm after 1 h at 400 °C and 10 kV/mm after 1 h at 600 °C), and is UL recognized to 94V-0 flame class, file E216697. Kaxite supplies hard mica sheet model KXT-B502 / B502G with density 2.45 g/cm³, continuous heat resistance 500/700 °C, peak 700/1000 °C, in standard sizes 1200 × 1000 mm and 600 × 1000 mm, thickness 0.2–80 mm.
