Grades: E75, X95, G105, S135

Drill Pipe
2-3/8" to 7-5/8" OD, Range 2 and 3

Heavy Weight
2-3/8" to 6-5/8" OD, Range 2 and 3

Drill Collars
2-7/8" to 14"

Connection threads: NC26, NC31, NC38, NC40, NC46, NC50, 5 1/2FH.6 5/8FH.
Internal Upset: IU, EU, IEU

Heavy weight drill pipe is a medium-weight drilling pipe, (referred standards in API SPEC 7-1). It has bigger wall thickness than common drilling pipe and smaller than drill collar. 

Mechanical Properties API Steel Drill Pipe