Drill Pipe Inspection Standards & Mechanism
When manufactured, the new drill pipe will be subjected by the manufacturer to a series of mechanical, tensile, and hydrostatic pressure tests & inspections in accordance with API Specification 5A and 5AX. This will ensure that the pipe can withstand specified loads. A joint of drill pipe will however be used in a number of wells. When it has been used it will undergo some degree of wear and will not be able to withstand the same loads as when it is new.
https://www.drillingmanual.com/drill-pipe-inspection-standards/