What are the main categories of πυρίμαχα τούβλα in terms of appearance and shape?

Refractory bricks can be divided into two categories from the appearance and shape:

① Special-shaped refractory bricks, the appearance shape is concave-convex surface, irregular shape, with edges and corners, round holes or arcs, and the shape can be cylindrical or trapezoidal.

②Commonly used refractory bricks, such as common types of T-size, G-size refractory bricks and rotary kiln refractory bricks, have clear size standards and are called commonly used refractory bricks. Each type of refractory brick produces different material properties and shapes and sizes, so they are all different, one type of refractory brick has the same weight.