API products (tubing, pup joints, and couplings) should be stenciled or a combination of stamping and stenciling as per API Spec. 5CT. The sequence of stencil marking is as follows:

Manufacturer’s name
Monogram marking
End finish
Size designation
Weight designation
Grade and type
Impact test temperature
Heat treatment
Manufacture process
Supplementary requirements
Hydrostatic test pressure
Type of thread
Size of drift
Serialization of Grades C-90 and T-95
Plating of coupling

Impact test temperature, heat treatment, supplementary requirements, type of thread, and plating of coupling are included if applicable. API Spec. 5CT