What is 650 kg/m3 calcium silicate board?

It is a high-density, structural-grade calcium silicate board for heavy-duty and back-up insulation, offering higher compressive strength than the 250 and 300 grades for steel ladle, tundish and furnace applications.

Density 650 kg/m³ · Structural High Density

High Density Calcium Silicate Board 650 kg/m³

Heavy Duty Structural Insulation for Furnace and Steel Applications

A high-density, structural-grade calcium silicate board built for mechanical load and back-up refractory insulation — the grade specified for steel ladle, tundish and furnace systems.

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High Mechanical Strength Thermal Stability Long Service Life Low Thermal Conductivity

High density 650 calcium silicate board steel ladle backup insulation

650 high density calcium silicate board structure

Why 650 kg/m³

Why Choose 650 kg/m³ Calcium Silicate Board

Higher Mechanical Load

Carries structural and mechanical load in Steel Ladle, Tundish, Furnace Cover and Heavy Equipment.

Longer Service Life

Reduces deformation, heat loss and maintenance over repeated thermal cycles.

Stronger Than Standard Grades

Compressive strength ≥ 5.0 MPa (725 psi) — several times the 250 and 300 grades — for demanding, load-bearing duty.

Technical Data

650 kg/m³ Specifications

Property	Value (Metric)	Value (US)
Density	650 kg/m³ ±10%	40.6 lb/ft³
Max Service Temperature	1000°C	1832°F
Compressive Strength	≥ 5.0 MPa	≥ 725 psi
Flexural Strength	≥ 3.0 MPa	≥ 435 psi
Thermal Conductivity @ 800°C	≤ 0.19 W/m·K	≤ 1.32 BTU·in/hr·ft²·°F
Reaction to Fire	A1 non-combustible	Non-asbestos

Made-to-order structural grade; values are indicative and confirmed on request. Density tolerance ±10%. Non-asbestos, A1 non-combustible.

Chemical Composition

Component	Unit	Value
SiO₂	%	52 Min
CaO	%	40 Min
Al₂O₃	%	0.3 Max
Fe₂O₃	%	1.0 Max
Loss on Ignition	%	7 Max

Dimensions (mm, ±2mm)

Length × Width	Thickness
1220×1220 · 1210×1210	10–100
1230×1000 · 1260×600	10–100
1000×500 · custom	to order

Thicker structural sections and custom sizes available to order.

Installing 650 calcium silicate board with mechanical fixing

Installation

How to Install

Anchor

Set studs/anchors — mechanical fixing is recommended for structural use.

Board

Mount the 650 boards onto the anchored surface.

Joint

Stagger and seal joints to prevent heat paths.

Cover

Apply the outer casing or refractory cover layer.

Mechanical fixing recommended for load-bearing and high-vibration installations.

FAQ

Frequently Asked Questions

What is 650 kg/m³ calcium silicate board?

A high-density, structural-grade calcium silicate board for heavy-duty and back-up insulation, with higher compressive strength than the 250 and 300 grades — used in steel ladle, tundish and furnace applications.

What is the difference between 400 and 650?

650 kg/m³ is denser with higher compressive strength and load-bearing capacity; 400 is lighter for general heavy-duty use. Choose 650 where mechanical load and structural backing matter most.

Can it replace refractory brick?

It is not a hot-face refractory. It is used as structural back-up insulation behind the refractory lining to cut heat loss and add backing — complementing rather than replacing dense refractory at the hottest face.

Can 650 board support load?

Yes. With compressive strength of at least 5.0 MPa (725 psi) it supports moderate structural and mechanical loads; share your load case for confirmation.

How is it installed?

Mechanical fixing is recommended: anchor, mount the board, seal joints and apply the cover layer.

What is the working temperature?

Service temperature is up to 1000°C (1832°F).

What thicknesses are available?

Standard thickness is 10–100 mm, with thicker structural sections and custom sizes available to order.

What export packaging do you provide?

Boards are film-wrapped, edge-protected and palletized or crated for safe international shipping.

High Density Calcium Silicate Board 650 kg/m³

Heavy Duty Structural Insulation for Furnace and Steel Applications