11 Characteristics of First Class Bricks

Following are the 11 properties/characteristics of a first-class brick:

1. First-class bricks are table moulded and they are burnt in Kilns.
2. These are well burnt in kilns.

3. The surface of the first-class brick should be smooth and rectangular.
4. The edges of the brick are perpendicular(Make an angle 90°) to the adjoining edges.

5. They are regular in shape and size with sharp edges and corners.
6. They shall be of uniform deep red colour.

7. They should be free from any cracks.
8. They should be free from chips, efflorescence, flaws and lumps of any kind.

9. Dry first-class bricks should not absorb water more than 16% of their own weight when immersed in water for 24 hours.
10. They emit a clear ringing sound when two bricks are struck each other.
11. The average compressive strength of the first-class bricks should not be less than 100kg/sq.cm and not more than 125 kg/sq.cm.