Definition:

Drill pipe is hollow, thin-walled, steel or aluminium alloy piping used on drilling rigs.

It is hollow to allow drilling fluid to be pumped down the hole through the bit and back up the annulus.

Manufacturer process:

Modern drill pipe is made from the welding of at least three separate pieces:

box tool joint

pin tool joint

the tube

The green tubes are received by the drill pipe manufacturer from the steel mill. The ends of the tubes are then upset to increase the cross sectional area of the ends. The tube end may be externally upset (EU), internally upset (IU), or internally and externally upset (IEU).