keevitus materjali läbiva fokuseeritud energiakiirega (elektron-, laserkiir, plasmakaar), mille puhul tekib energiakiire all läbiv ava mis keevitamisel sulametalliga täitudes moodustab keevisõmbluse (vt läbistav keevitustehnika), a technique in which a concentrated heat source (electron beam, laser beam etc) penetrates completely through a workpiece, forming a hole (keyhole) at the leading edge of the weld pool; as the heat source progresses, the molten metal fills in behind the hole to form the weld bead (see: keyhole technique)