A bone fixation element (100) for fixing a bone fixation plate (200) to a bone (5) is disclosed. The bone fixation element (100) includes a shank (140) receivable into the bone (5) and a head (120) securable to the bone fixation plate (200). The head (120) has an external locking thread (160) including a first thread section (166) adapted to progressively deform a portion of a hole (220) in the bone fixation plate (200) as the head (120) of the bone fixation element (100) is inserted into the hole (220). The external locking thread (160) further includes a second substantially parallel thread section (164) adapted to engage with a portion of the hole (220) deformed by the first thread section (166) to thereby secure the head (120) of the bone fixation element (100) to the bone fixation plate (200). The bone fixation element (100) may be a variable angle locking screw.
