As the wrench is used for head bolts that screw into the round feature but creates a square Groove within which to get – a general tightening that set-screw (SET SCREW)
The wrench is used for the screw bolt made a round head. But creating a triangle inside groove for tightening - loosening, which is commonly referred to Seth - screw (SET SCREW).
A wrench used for screw bolt at the head is rounded, but build on ภายในเพื่อ Khan square groove - relax, which is commonly referred to as set - screw. (SET SCREW) .