The ranked field covers 26 companies across 55 records, with the leading assignee holding 7 records and the top 5 combined holding 52.7% of all records in scope. That leaves a long tail of smaller filers, so no single company controls the field outright. Fifth place holds 4 records and tenth place holds 2, meaning the mid-table is closely spaced and worth watching for shifts.

Filing peaked at 8 records in 2017 and has since cooled, with the 2021-to-2024 window showing a move from 5 records to 2, a -60% change. Because publication lags filing by roughly 18 months, the years after 2024 are still filling in and should not yet be read as a continued decline. The pattern so far looks like a maturing field that filed its core claims earlier rather than one still in a land-grab phase.

The largest IPC class is F16B (fasteners such as bolts and rivets), appearing in 36.4% of the 55 records, followed by C09D (coatings, paints and inks) at 29.1% and C23C (coating and surface deposition) at 21.8%. Smaller but present classes include B32B laminates, C21D heat treatment, C08K polymer additives, B05B spraying and B64D aircraft equipment. Because records often carry multiple classes, most contested claims combine a fastener geometry element with a coating chemistry or deposition element.