Foreign Object Damage
Driving over hard, pointed objects like nails, screws and the like can pierce the tire.
This always leads to tire damage.
Damage from embedded foreign bodies
Frequently, the foreign object -marking- is so securely embedded in the tire that it will not free itself even at higher speeds. Due to this, it can act as a plug and seal the tire relatively well. The result is gradual loss of pressure which the driver does not notice immediately but which can lead to sudden and complete tire failure.
NOTE:
No repair should be attempted on steel belted tires of which the structure has been punctured by a foreign object.