Flanged end or outlet connection in which thread-anchored studs screwed into tapped holes replace the holes for bolt studs.
Source: API SPEC 6A, Specification for Wellhead and Christmas Tree Equipment, Twentieth Edition, October 2010 (Addendum November 2012). Global Standards
Connection in which thread-anchored studs are screwed into tapped holes.
Source: API Specification 16A, Specification for Drill-through Equipment, Fourth Edition, April 2017. Global Standards
Source: API SPEC 16A, Specification for Drill-through Equipment, Third Edition, June 2004 (Errata/Supplement November 2004). Global Standards