Insulation Board — High Strength Millboards for 850 °C to 1,500 °C
Asbestos-free, rigid insulation board made from wollastonite, calcium silicate and alkaline-earth silicate fibres — for ladle and tundish back-up, kiln and furnace insulation, burner and oven linings, fire doors and high-temperature gaskets. Classification 850–1,500 °C (short-term to 1,800 °C), λ 0.11 W/m·K at 400 °C, compressive strength up to 30 MPa.
Price: ₹85–150 per kg (US$ 0.89–1.57/kg) — about ₹850–1,500 per m² at 10 mm. Cut to size or CNC-machined into gaskets, washers and rings at our Faridabad plant; supplied across India and exported to the UAE, Saudi Arabia, Qatar, Kuwait and 45+ countries.
Insulation board price 2026
Wedge insulation boards are priced by weight: ₹85–150 per kg, ex-works Faridabad, excluding GST and freight. The lower end applies to 850–1,000 °C grades (RIMB 1000, HSI 1000) in regular sheet sizes and larger quantities; the upper end to 1,250–1,500 °C grades, bio-soluble HSI 1250, roller-disc millboard and small CNC-machined lots. At ~1,000 kg/m³, each 1 mm of thickness weighs about 1 kg per m².
| Board thickness (1,000 kg/m³ grades) | Weight per m² | Price per m² | US$ per m² |
|---|---|---|---|
| 3 mm | ≈ 3 kg | ₹255–450 | $2.67–4.71 |
| 5 mm | ≈ 5 kg | ₹425–750 | $4.45–7.85 |
| 6 mm | ≈ 6 kg | ₹510–900 | $5.33–9.41 |
| 8 mm | ≈ 8 kg | ₹680–1,200 | $7.11–12.55 |
| 10 mm | ≈ 10 kg | ₹850–1,500 | $8.89–15.69 |
| 12 mm | ≈ 12 kg | ₹1,020–1,800 | $10.67–18.83 |
| 15 mm | ≈ 15 kg | ₹1,275–2,250 | $13.34–23.54 |
| 20 mm | ≈ 20 kg | ₹1,700–3,000 | $17.78–31.38 |
| 25 mm | ≈ 25 kg | ₹2,125–3,750 | $22.23–39.23 |
HSI 1250 (800 kg/m³) and RIMB 1500W (900–980 kg/m³) weigh 5–20 % less per m² at the same thickness. Prices are indicative web price bands for 2026 (US$ at ₹95.6 = $1), not an offer — the firm price, sheet size and lead time are confirmed in our written quotation.
Which insulation board for which temperature?
Choose a classification temperature at least 100–150 °C above the hot-face temperature. For the lowest heat loss behind a refractory, combine a thin high-strength board with microporous insulation.
| Grade | Classification | Density | λ at 600 °C | Compressive | Best for |
|---|---|---|---|---|---|
| RIMB 850 (ceramic-fibre millboard) | 850 °C | 1,000 kg/m³ | 0.15 W/m·K | 6 MPa | Appliance and oven gaskets |
| HSI 1000 | 1,000 °C | 1,000 kg/m³ | 0.12 W/m·K | 8–10 MPa | Ladle, kiln and furnace back-up; fire doors |
| RIMB 1000HD | 1,000 °C | 950 kg/m³ | 0.14 W/m·K | 14 MPa at 10 % | Load-bearing heat shields, pipe supports, gaskets |
| RIMB 1000W / 1000A | 1,000 °C | 1,000–1,150 kg/m³ | 0.12–0.14 W/m·K | 8 MPa | General-purpose millboard, expansion joints |
| RIMB 1100A | 1,100 °C | 1,000 kg/m³ | 0.13 W/m·K | 12 MPa | Cement and lime kiln back-up |
| HSI 1250 (AES, bio-soluble) | 1,250 °C | 800 kg/m³ | 0.12 W/m·K | 12 MPa | Export/EU projects, high-wear hot zones |
| RIMB 1250W / 1260A | 1,250–1,260 °C | 1,000–1,100 kg/m³ | 0.12–0.15 W/m·K | 12 MPa | Tundish and ladle gaskets, burner blocks |
| RIMB 1260AS (roller disc) | 1,300 °C | 800–1,000 kg/m³ | 0.12 W/m·K | 30 MPa | Stainless-steel furnace roller coverings |
| RIMB 1500W | 1,500 °C (1,800 °C short-term) | 900–980 kg/m³ | 0.15 W/m·K | 12 MPa | Highest-temperature gaskets and seals |
HSI 1000 — high strength insulation board
Our most-ordered insulation board. Calcium silicate and wollastonite fibre board with high compressive strength, low shrinkage and high electrical resistance at temperature — the standard back-up board behind ladle, tundish and kiln refractories, and the core of fire doors, lift doors and safes. Also supplied as moulded pipe sections.
| Property | HSI 1000 |
|---|---|
| Base material | Wollastonite fibres & calcium silicate |
| Classification temperature | 1,000 °C |
| Density | 1,000 kg/m³ |
| λ at 400 / 600 / 800 °C | 0.11 / 0.12 / 0.14 W/m·K |
| Tensile / flexural strength | 5 / 6 MPa |
| Compressive strength | 8–10 MPa |
| Shrinkage at 1,000 °C | < 1 % |
| Loss on ignition | 8 % |
Datasheet: HSI 1000 TDS (PDF) · Related: Insulation Millboard · Wollastonite Board · Best ladle insulation boards
RIMB 1000HD — high density insulation board
High-density wollastonite calcium silicate board reinforced for load: heat shields, pipe supports, furnace back-up under load, metal-clad gasket fillers and high-temperature electrical insulation. Compression resistance rises steeply with strain — 8 MPa at 5 % and 35 MPa at 20 %.
| Property | RIMB 1000HD |
|---|---|
| Classification temperature | 1,000 °C |
| Density | 950 kg/m³ |
| λ at 400 / 600 / 800 °C | 0.12 / 0.14 / 0.18 W/m·K |
| Tensile / flexural strength | 5 / 8 MPa |
| Compressive at 1 / 5 / 10 / 20 % | 1.9 / 8 / 14 / 35 MPa |
| Shrinkage at 1,000 °C | < 1 % |
| Loss on ignition at 1,000 °C | 6 % |
Datasheet: RIMB 1000HD TDS (PDF)
HSI 1250 — bio-soluble high strength insulation board
Alkaline-earth silicate (AES) fibre board made with exonerated, low bio-persistent fibres that meet European regulatory requirements. Continuous service to 1,250 °C (1,300 °C short-term), very low shrinkage and 12 MPa compressive strength at only 800 kg/m³ — the choice for export and EU-specified projects.
| Property | HSI 1250 |
|---|---|
| Base material | AES low bio-persistent fibres |
| Classification temperature | 1,250 °C |
| Density | 800 kg/m³ |
| λ at 400 / 600 / 800 °C | 0.11 / 0.12 / 0.13 W/m·K |
| Tensile / flexural strength | 5 / 6 MPa |
| Compressive strength | 12 MPa |
| Shrinkage at 1,000 °C | < 1 % |
Datasheet: HSI 1250 TDS (PDF)
RIMB W grades — 1,000 / 1,250 / 1,500 °C insulation board
Wollastonite, calcium/magnesium silicate and high-temperature clay millboards with high electrical resistance, good compressibility and recovery for gasketing (ASTM F36).
| Property | RIMB 1000W | RIMB 1250W | RIMB 1500W |
|---|---|---|---|
| Classification / short-term max | 1,000 / 1,400 °C | 1,250 / 1,600 °C | 1,500 / 1,800 °C |
| Density | 1,100–1,150 kg/m³ | 1,000–1,100 kg/m³ | 900–980 kg/m³ |
| λ at 200 °C | 0.12 W/m·K | 0.13 W/m·K | 0.13 W/m·K |
| λ at 600 °C | 0.14 W/m·K | 0.15 W/m·K | 0.15 W/m·K |
| λ at 1,000 °C | 0.18 W/m·K | 0.20 W/m·K | 0.21 W/m·K |
| Electrical resistance (Ω×10⁹/cm²) | 7.9 | 4.2 | 2.4 |
| Tensile / flexural strength | 5 / 7 MPa | 5 / 6 MPa | 5 / 6 MPa |
| Compressive strength | 8 MPa | 12 MPa | 12 MPa |
| Shrinkage at 1,000 °C | 1.6 % | 1 % | < 1 % |
| Compressibility / recovery (ASTM F36) | 15 / 40 % | 10 / 50 % | 10 / 60 % |
RIMB A millboards and ceramic-fibre millboards
| Property | RIMB 1000A | RIMB 1100A | RIMB 1260A |
|---|---|---|---|
| Colour | Brown / white | Buff | White |
| Classification / density | 1,000 °C · 1,000 kg/m³ | 1,100 °C · 1,000 kg/m³ | 1,260 °C · 1,000 kg/m³ |
| λ at 400 / 600 / 800 °C | 0.11 / 0.12 / 0.14 | 0.12 / 0.13 / 0.14 | 0.11 / 0.12 / 0.13 |
| Compressive / flexural | 8 / 7 MPa | 12 / 6 MPa | 12 / 6 MPa |
| Shrinkage at 1,000 °C | 2 % | 1.8 % | 1.6 % |
Ceramic-fibre based millboards (alumino-silicate and mineral wool fibre): RIMB 850 (850 °C, compressive 6 MPa), RIMB 1000 (1,000 °C, 10 MPa) and RIMB 1200 (1,200 °C, 14 MPa, shrinkage 1.6 % at 1,000 °C) — softer and more compressible (15–30 % ASTM F36) for sealing gaskets. See also Ceramic Millboard, Non-Asbestos Millboard and Wedge Millboard 1700.
RIMB 1260AS — millboard roller discs for stainless-steel furnaces
Roller discs
AES fibre millboard, 1,300 °C, shot-free so it does not mark stainless strip. 800–1,000 kg/m³, compressive 30 MPa, shrinkage 1.5 % at 1,000 °C.
Furnace roller covering
Discs are stacked and compressed on the roller shaft. Before service, soak the rollers at about 1,100 °C for 24 hours in the stand-by position.
Rings for centrifugal casting
Punched millboard rings and washers for centrifugal-casting moulds and glass-roller mandrels. Millboard rings · RIMB 1260AS TDS
Insulation board gaskets, washers and rings — cut to your drawing
Every grade can be cut, punched or CNC-routed to drawing at Faridabad: flange gaskets, burner and oven gaskets, appliance insulation plates, washers for glass-roller mandrels, ladle and tundish gaskets, and long machined strips. Send a DXF/PDF drawing with quantity for a price per piece.
Flange gaskets
Bolt-hole gaskets for burners, ducts and hot-gas flanges.
Burner & oven gaskets
Die-cut profiles for oil and gas burners, dryers and ovens.
Appliance plates
High electrical resistance at temperature for heaters and home appliances.
Washers
Washers for glass rollers on mandrels and metal-clad gasket fillers.
Machined strips
Precision strips for expansion joints, door edges and seals.
CNC-routed parts
Multi-hole plates and complex profiles routed from full sheets.
Online listings: Non-Asbestos Millboard for Gaskets · Insulation Board
How thick should the insulation board be?
Catalogue design values for a single layer of Wedge high strength board at the hot face. Where the cold face must be near ambient, add a calcium silicate or microporous back-up layer — use our insulation thickness calculator or ask our engineers for a heat-loss calculation.
| Hot face | Board | Thickness | Cold face |
|---|---|---|---|
| 600 °C | HSI 800 | 10 mm | 270 °C |
| 800 °C | HSI 800 | 15 mm | 289 °C |
| 900 °C | HSI 1000 | 20 mm | 290 °C |
| 1,000 °C | HSI 1000 | 25 mm | 284 °C |
| 1,100 °C | HSI 1100 | 30 mm | 290 °C |
| 1,200 °C | HSI 1200 | 30 mm | 348 °C |
Where Wedge insulation boards are used
Steel ladles & tundishes
Back-up board between the working refractory and the steel shell keeps shell temperature and heat loss down.
Behind refractory bricks
Thin, high-strength board takes brick load without crushing — ladles, converters, furnaces.
Cement & lime kilns
Preheater, cyclone and kiln-hood back-up insulation; burner and duct gaskets.
- Furnaces, boilers, dryers and ovens: back-up insulation, burner and oil/gas burner insulation, expansion joints.
- Glass and metals: glass-roller washers, centrifugal-casting gaskets, stainless-steel roller discs, metal-casting gaskets.
- Fire protection: fire-resistant doors, lifts, safes and cupboards — see fire door components.
- Electrical: appliance insulation gaskets and high-temperature electrical insulation.
Related ranges: calcium silicate boards · ceramic fibre boards · microporous insulation · vermiculite boards (60–240 min fire rating) · all high-temperature insulation.
Wedge RIMB insulation board & millboard datasheet
RIMB W and ceramic-fibre grades, properties and applications
Why buy insulation board from Wedge Industries Limited
- Nine grades from 850 °C to 1,500 °C, including bio-soluble AES boards for export projects.
- Asbestos-free; easy to cut, punch and machine; CNC cutting to drawing in Faridabad.
- Board, gaskets, calcium silicate, microporous and ceramic fibre from one supplier — the whole lining specified together.
- Dispatch across India; export to the GCC (UAE, Saudi Arabia, Qatar, Kuwait), Nepal, Africa and Europe.
- TDS and batch test certificates supplied with every order.
Insulation board — frequently asked questions
What is the price of insulation board in India?
Wedge high strength insulation board costs ₹85–150 per kg (US$ 0.89–1.57/kg), ex-works, excluding GST and freight. At about 1,000 kg/m³ that is roughly ₹850–1,500 per m² for 10 mm board. 1,000 °C grades sit at the lower end; 1,250–1,500 °C, bio-soluble and CNC-machined parts at the upper end.
What temperature can insulation board withstand?
Wedge grades are classified from 850 °C (RIMB 850) to 1,500 °C (RIMB 1500W), with short-term peaks up to 1,800 °C. For most ladle, kiln and furnace back-up duties HSI 1000 or RIMB 1000 is used; HSI 1250 and RIMB 1260 for hotter zones.
What is the difference between insulation board and millboard?
Millboard is a dense, fibre-reinforced insulation board (about 800–1,150 kg/m³) made on a board machine from wollastonite, calcium silicate or ceramic fibres and clay binders. It is stronger and easier to punch than low-density insulation board, so it is used where the board must carry load or seal a joint.
Is Wedge insulation board asbestos-free?
Yes. All RIMB and HSI boards are asbestos-free. HSI 1250 and RIMB 1260AS use low bio-persistent alkaline-earth silicate fibres that meet European regulatory requirements.
Can you cut insulation board into gaskets?
Yes. We cut, punch and CNC-route flange gaskets, burner gaskets, washers, rings and strips to your drawing. Send a DXF or PDF with the quantity for a price per piece.
How strong is high strength insulation board?
Compressive strength is 8–10 MPa for HSI 1000, 12 MPa for HSI 1250 and RIMB 1250W, up to 35 MPa at 20 % compression for RIMB 1000HD and 30 MPa for RIMB 1260AS roller-disc board.
Get an insulation board quote in 24 hours
Tell us the grade (or hot-face temperature), thickness, sheet size or drawing and quantity — we confirm the right board and a firm price.