API thread Gauges usage:

Rotary shouldered thread connection is used, such as drill collars, drill pipe, the drill stabilizer and adapter and other drilling tools and drill stem elements connected. Production and inspection in accordance with the standards API SPEC **2 "rotary shouldered threaded connections. The main form of rotary shouldered thread connection within the flat type (IF), consistently eye (FH), digital type (NC), the normal form (REG). Of *2 Preferred connection of the kind of right-handed or left-handed.

Rotary shouldered thread for drilling tools and drill string components connected such as drill pipe, drill and adapter

API Thread Gauges:

API Spec 5B:

CSG **1/2 to *0"

LCSG **1/2 to *0"

LP 1/8 to *2"

BCSG **1/2 to 6"

TBG1.**0 to **1/2"

UPTBG 1.**0 to **1/2"

API Spec **2

NC*0 to NC*7

REG **3/8 to **5/8"

FH **1/2 to **5/8"

IF **3/8 to **1/2"