Spall are flakes of a material that are broken off a larger solid body. One common form of spalling occurs due to moisture freezing inside cracks in rock, cracking off the outer surfaces.

Spalling is also used to describe the flakes of metal chipped off the inside of armor plating on tanks and other armored fighting vehicles due to attacks on the outside creating a shock wave that travels through the armor and breaks the softer metal on the inside. Spalling is an intended effect of the high explosive squash head anti-tank round and of many other munitions which may not be powerful enough to pierce the armor of a target. This spall is often very damaging and may result in a partial or complete "kill."

See also

• anti-tank
• Misznay-Schardin effect