The phrase "a class of solid" is correct and usable in written English.
It can be used in scientific or technical contexts to categorize or describe a group of solid materials with similar properties.
Example: "In materials science, we often study a class of solid that exhibits unique thermal conductivity characteristics."
Alternatives: "a category of solid" or "a type of solid".
Thermoelectric power generator, any of a class of solid-state devices that either convert heat directly into electricity or transform electrical energy into thermal power for heating or cooling.
There exists a class of solids called network solids in which the bonding is essentially due to a network of covalent bonds that extends throughout the solid.
System (1.1) is a simplified model for a class of solid-liquid phase change problems.
Gravity thickeners and clarifiers represent a class of solid-walled separator, where gravitational forces are used to raise the concentration of a suspension through sedimentation to produce a thickened sludge with a clear liquid as overflow.
A class of solid-fluid problems, involving the removal of heat from a heated solid cylinder by a surrounding annular-flow fluid, is then discussed in detail; analytical solutions are obtained by expansion in terms of the above eigenvectors.
Semiconductor, any of a class of crystalline solids intermediate in electrical conductivity between a conductor and an insulator.
The elastostatic fields and free-vibration characteristics are studied for a class of continuous solids in the shape of homogeneous or layered pentahedral pyramids.
Metal borides are a class of inorganic solids that is much less known and investigated than for example metal oxides or intermetallics.
Sedutto's, the nation's first so-called superpremium ice cream -- high in butterfat, with plenty of egg yolks, less air whipped into it and a better class of solid ingredients flavoring the whole -- was founded in New York in 1922.
Pharmaceutical cocrystals are emerging as a new class of solid drugs with improved physicochemical properties, which has attracted increased interests from both industrial and academic researchers.
