2760 F Girtech Usm-5 Heavy Duty Fire Brick. GIRtech USM is a special heavy duty thin firebrick which are used for masonry and lining of any household heating units, fireplaces cladding, mini-forges, as well as for household buildings. Maximum operating temperature is no more than 2760 F. Refractory masonry must be done on a fireclay/alumina mortar, for example GIRtech CONTACT-40. Before performing work, it is necessary to moisten the contact surface with some water. It is possible to use a cement mortar only for masonry of non-thermal household units, without subsequent ignition. GIRtech USM could be cuted or processed with a special tool if necessary. It is made from eco-friendly natural components and safe for human health. This product is not intended for use in industrial units where contact between the refractory lining and molten metals is possible. Appearance, sizes: hearth plates 9.0*4.5*1.25 inches Composition: fireclay, quarz sand Net Weight, lb 3.97 Minimum refractoriness: 2 760 F Interconnected porosity, % 18.5 Apparent specific graviry, ln/in3 69 - 72 Compressive strenghth, psi 2 700 - 3 300 Thermal expansion coefficient (2 372 F): 0% Thermal resistance, thermal cycles (32F to 1700F) 40 Safety: non toxic, safe for human health GIRtech USM ? chamotte firebrick has improved thermal conductivity compared to traditional chamotte products. Firebrick can be used in any type of domestic heating units, such as brick fireplaces, steel furnaces, heating stoves, barbecues and barbecue complexes, ceramics kilns and blacksmith forge. It can be used both for arranging the hearth of the furnace and for lining the inner surface of the furnace. Could be cutted or processed with a special tool if necessary. It is made from eco-friendly natural components and safe for human health