É a face frontal do fio de rosca. É a parte que terá o primeiro contato do tubo com a luva no início do acoplamento.
Meaning
The term "stab flank" designates the side wall surface of the thread that faces toward the outer end of the respective pin or box member e supports forces compressing the joints toward each other such as the weight of the upper tubular member during the initial makeup of the joint or such as a force applied to push a lower tubular member against the bottom of a bore hole (i.e., compressive force)