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drill pipe and tool joints are covered in detail by API
specifications, which are followed closely around the world.
API specifications cover two grades of drill pipes, based on
the physical properties of each grade. They are: Grade D,
minimum yield strength 55,000 psi; Grade E, minimum yield
strength 75,000 psi. Also available are non-API Grade G,
minimum yield strength 105,000 psi; and Grade S, minimum yield
strength 135,000 psi.
Drill pipe is furnished internal-upset, external-upset,
internal-external-upset an in random lengths as follows: Range 1:
18-ft to 22-ft inclusive; Range 2: 27-ft to 30-ft inclusive; Range 3:
38-ft to 45-ft inclusive.
Note: Internal-external-upset is for weld-on tool joints only.
Drill pipe sizes and weights extend from 2 3/8-in. OD 4.85 lb/ft to
6 5/8-in. OD 25.20 lb/ft. API Spec. 5A covers in detail the various
properties of all tubular goods, including drill pipe. (Refer to the
latest revised issue for current standards.)
Armco’s Engineering Data Handbook, 1966 ed. covers basic
specifications of both API and non-API grades of drill pipe.
Tool joints, as used on drill pipe, have much in common
with connections on drill collars, or perhaps the other way around.
Tool joints are usually not an integral part of drill pipe as the drill
collar connections but are semi-permanent attachments to each
length of pipe. Much progress has been made in tool joint design
both as to relative dimensions and as to metallurgy. Tool joints in
new condition are no longer weaker than the body of the pipe but
may become with the excessive wear and abuse.
Two methods of attaching tool joints to drill pipe are still in
use: weld-on and threaded connection.
Weld-on types are rapidly gaining preference in most areas;
however, the threaded types have the advantage of being field
replaceable. The integral type joint also would seem to offer some
advantage but like the weld-on type it too must be produced in a
plant or a shop.

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