Specification for Rotary Drill Stem Elements
Addendum 4 of API 7-1 (R2015) - Specification for Rotary Drill Stem Elements has been published on February 1st, 2019.
Main changes/sections amended are:
- §7.10 Marking of Lift Subs (Figure 6 - type D)
- Table 11 minimum surface hardness of dimension DR of type B Drill Stem Subs
- Table 12 dimension of lift-subs upper lift diameters (link to table 7 of API 8C)
- Table 12A dimension data for lift sub upper lift diameter (link to table 7 of API 8C)
- Table C.1 mechanical properties and tests for heavy section tools