Overview
A rigid mica board — also sold as mica sheet, mica plate or micanite board — is a high-pressure laminate made from muscovite, phlogopite or synthetic mica paper, bonded with silicone resin and cured under controlled heat and pressure into a flat, rigid sheet. Mica brings very high dielectric strength and arc resistance; the heat-stable silicone binder keeps the board electrically insulating and dimensionally stable at temperatures where glass-epoxy laminates (G10 / FR4, 130–180 °C temperature index) cannot be used.
WedgeMICA rigid mica boards from Wedge Industries Limited come in three grades with continuous temperature indices of 550 °C, 800 °C and 1100 °C. Every grade is rated UL 94 V-0 and machines readily into arc chutes, arc barriers, busbar supports, coil insulation, washers and custom parts to drawing.
WedgeMICA mica insulation catalogue 2026 (PDF, 6 pages, 1.3 MB) — Rigid mica board grades, technical data, sizes and ordering codes for the full range of mica boards, sheets, rolls, tubes, gaskets and machined parts.
Rigid mica board grades
| Grade | Mica paper | Colour | Temp. index | Primary use |
|---|---|---|---|---|
| WMB-M550 | Muscovite | Cream | 550 °C | Highest tensile and flexural strength — switchgear, busbar supports, arc barriers |
| WMB-P800 | Phlogopite | Brown | 800 °C | Furnace and induction coil insulation, EAF / LF components |
| WMB-S1100 | Synthetic | White | 1100 °C | Highest temperature duty, highest arc resistance and dielectric strength |
Mica sheet specifications — technical data
Typical values from TDS WIL-TDS-MICA-001 (issue 19-10-2026). They are typical test values, not specification limits; batch values are reported on the Material Test Certificate. NA = data not available.
| Property | WMB-M550 | WMB-P800 | WMB-S1100 | Unit |
|---|---|---|---|---|
| Density (specific gravity 2.25) | 2250 | 2250 | 2250 | kg/m³ |
| Water absorption | 0.35 | < 1.0 | < 1.0 | % |
| Tensile strength — lengthwise | 195 | 110 | 110 | MPa |
| Flexural strength — lengthwise | 166 | NA | NA | MPa |
| Shear strength | 207 | 207 | 207 | MPa |
| Izod impact strength | 267 | 267 | 267 | J/m |
| Bonding strength | 2.67 | 2.67 | 2.67 | kN |
| Rockwell hardness | M70 | M70 | M70 | — |
| Dielectric strength (minimum) | 19.7 | 21.7 | 23.6 | kV/mm |
| Breakdown strength (typical) | 25 | 25 | 25 | kV/mm |
| Arc resistance (minimum) | 420 | 420 | 500 | s |
| Relative temperature index (continuous) | 550 | 800 | 1100 | °C |
| Flammability | V-0 | V-0 | V-0 | UL 94 |
Sizes and supply
| Item | Standard supply |
|---|---|
| Standard sheet size | 1000 × 1200 mm; 1000 × 2400 mm |
| Thickness range | 1 mm to 50 mm |
| Cut pieces and machined parts | Cut to size, CNC routed, drilled, milled and threaded to customer drawing |
| Ordering example | WMB-P800-10-1012 = phlogopite rigid board, 10 mm, 1000 × 1200 mm |
Mica board vs G10 / FR4 glass-epoxy
Choose mica board where the part sees heat, arcing or molten-metal radiation as well as voltage — furnace, EAF / induction, smelting and heater duty. Glass-epoxy laminates remain the economical choice for ambient-temperature switchgear and panel parts below 130 °C. Glass-epoxy values are typical published values for comparison only.
| Property | WMB-M550 | WMB-P800 | WMB-S1100 | G10 / FR4 | Unit |
|---|---|---|---|---|---|
| Relative temperature index | 550 | 800 | 1100 | 130 | °C |
| Arc resistance (min.) | 420 | 420 | 500 | 120–130 | s |
| Dielectric strength (min.) | 19.7 | 21.7 | 23.6 | 19.7–21.7 | kV/mm |
| Flammability | V-0 | V-0 | V-0 | HB (G10) / V-1 (FR4) | UL 94 |
Mica sheet price
WedgeMICA rigid mica boards are quoted on request. The price depends on the mica type (muscovite, phlogopite or synthetic), thickness, size or drawing, quantity and any test requirement, so every enquiry gets a firm quotation in ₹ INR and $ USD with the technical data sheet attached. MOQ and lead time are confirmed with each quotation.
Quote the Wedge SKU to speed things up: family-grade-thickness (mm)-size. Size codes: 1006 = 1000 × 600 mm, 1012 = 1000 × 1200 mm, 1024 = 1000 × 2400 mm, CUT = cut to drawing.
Applications
- Switchgear and circuit breakers — arc chutes, arc barriers, phase barriers and busbar supports (WMB-M550 / WMB-S1100).
- Induction furnaces — coil supports, spacers, slip-plane and top / bottom panel insulation (WMB-P800).
- EAF / LF — electrode clamp, mast arm, roof-lift and bus tube insulation (WMB-P800 and machined parts).
- Smelting pots and cells — busbar, anode clamp and cradle insulation; resistor banks (WMB-P800 / WMB-S1100).
- Heaters and enclosures — heating elements, heater frames, high-heat enclosures, transformer and motor insulation parts.
Machining and installation
- Saw, CNC route, drill, mill, turn and tap with carbide tooling; use sharp tools and moderate feed to avoid edge delamination.
- Support the sheet fully when drilling and back it with a sacrificial board to prevent break-out.
- Machine under local dust extraction and wear an FFP2 / P2 dust mask, safety glasses and gloves.
- On first heating above about 300 °C a small amount of binder may burn off with light smoke — ventilate during the first heat-up.
- Store sheets flat, indoors, dry and away from heavy point loads, in the original packing until use.
Prefer finished parts? See machined mica parts to drawing.
Safety and compliance
UL 94 V-0 on all three grades. The MSDS classifies WedgeMICA silicone-bonded mica laminates as not hazardous under CLP (EC 1272/2008) in the form supplied; mica content is ≥ 88 % (muscovite CAS 12001-26-2, phlogopite CAS 12251-00-2, synthetic fluorophlogopite CAS 12003-38-2) with ≤ 12 % cured silicone binder. Customs classification HSN 6814.
Why buy mica insulation from Wedge Industries Limited
- One source for the whole WedgeMICA range — rigid boards, heater plates, flexible sheets, rolls, tubes, gaskets, natural muscovite mica and machined parts — in muscovite, phlogopite and synthetic mica.
- Technical Data Sheet with every quotation and a Material Test Certificate with batch test values on every delivery.
- Sample pieces of board, sheet and natural mica available for evaluation and approval before bulk orders.
- In-house CNC fabrication: parts cut, drilled, milled, turned and threaded to your DXF / DWG / PDF drawing, counted and labelled by drawing number.
- Export packing — sheets packed flat and interleaved on wooden pallets or in wooden cases — for customers in 45+ countries across the Gulf, Europe, Africa and South East Asia.
- Office in Gurugram (Galleria Tower, DLF Phase 4) with group companies in the United Kingdom and Hong Kong for export documentation.
Frequently asked questions
What is a rigid mica board?
A rigid mica board, also called mica sheet, mica plate or micanite board, is a laminate of muscovite, phlogopite or synthetic mica paper bonded with silicone resin and pressed under heat and pressure into a flat rigid sheet. WedgeMICA boards combine high dielectric strength with temperature indices of 550, 800 or 1100 °C and a UL 94 V-0 rating, and are machined into arc barriers, busbar supports, coil insulation and washers.
What is the difference between muscovite, phlogopite and synthetic mica sheet?
Muscovite grade WMB-M550 (cream, 550 °C) has the best electrical and mechanical strength, with 195 MPa tensile strength. Phlogopite grade WMB-P800 (brown, 800 °C) has higher heat resistance and is the standard for induction furnace and EAF / LF insulation. Synthetic grade WMB-S1100 (white, 1100 °C) has the highest temperature index, 23.6 kV/mm minimum dielectric strength and 500 s arc resistance.
What sizes and thicknesses of mica board are available?
Standard sheets are 1000 × 1200 mm and 1000 × 2400 mm in thicknesses from 1 mm to 50 mm. Wedge Industries Limited also supplies cut pieces and CNC routed, drilled, milled and threaded parts to customer drawing. Order by SKU, for example WMB-P800-10-1012 for a 10 mm phlogopite board of 1000 × 1200 mm.
What is the dielectric strength of mica sheet?
Minimum dielectric strength is 19.7 kV/mm for WMB-M550, 21.7 kV/mm for WMB-P800 and 23.6 kV/mm for WMB-S1100, with a typical breakdown strength of 25 kV/mm. Dielectric strength depends on thickness and test method, so batch values are reported on the Material Test Certificate supplied with every delivery.
Can mica board replace G10 or FR4?
Yes, where the part sees heat or arcing. G10 / FR4 glass-epoxy has a temperature index of about 130 °C and arc resistance of 120 to 130 s, while WedgeMICA boards are rated 550 to 1100 °C with 420 to 500 s arc resistance and UL 94 V-0. For ambient-temperature panel parts below 130 °C, glass-epoxy remains the cheaper choice.
What is the price of mica sheet in India?
WedgeMICA rigid mica sheet is priced on request because the price depends on mica type, thickness, sheet size or drawing and quantity. Send the SKU or grade, thickness and quantity using the Get Price button and Wedge Industries Limited returns a firm quotation in INR and USD with the technical data sheet; MOQ and lead time are confirmed with each quotation.
Related mica products
- Mica insulation guide 2027 — types, temperature ratings and how to specify
- Mica insulation — full WedgeMICA range, grades and selection guide
- Mica heater plates WMH (0.15–1.5 mm)
- Flexible mica sheet WMF
- Mica roll for induction furnace WMR
- Mica tubes and bushes WMT
- Mica gasket sheet WMG
- Natural ruby muscovite mica WMN
- Machined mica parts to drawing WMX
- EV battery mica barrier plate
- EV busbar mica insulation sheet
- Electrical insulation products
- High-temperature insulation
- Microporous insulation
Request a quotation for rigid mica boards
Send the Wedge SKU or the grade, thickness, size or drawing, quantity and any MTC or dielectric test requirement. Wedge Industries Limited returns a technical data sheet, a sample on request and a firm price in ₹ INR and $ USD.
