The ranked leader holds 24 of the 93 records in this dataset, well ahead of the fifth-placed company at 5 and the tenth-placed company at 2. The top 5 assignees combined account for 53.8% of all 93 records, and the top 10 combined reach 69.9%, so filing activity is concentrated among a small group rather than spread evenly across the 41 ranked companies. That said, a long tail of single- or double-filing entrants still makes up a meaningful share of the total, particularly around casting- and forging-specific applications.

Filings peaked at 10 records in 2023, and the 2021-to-2024 window shows a modest -14% move from 7 to 6 filings. It would be a mistake to read 2025 or 2026 figures as a further decline, because publication typically lags actual filing by roughly 18 months, so the most recent years in any patent trend are always undercounted at the point of publication. The honest read is a plateau after a mid-decade peak, with the true 2025-2026 picture not yet visible.

Casting inspection (B22D), forging inspection (B21J), and heat-treatment or non-ferrous metal condition monitoring (C21D, C22F) each account for only 4.3% of the 93 records, compared with 78.5% for the core material-testing class G01N. These narrower application domains have not attracted the same filing density as general weld radiography and image-quality-indicator methods, and co-assignee collaboration across organisations is rare in this dataset overall, with only two recorded pairs. That combination suggests room for claims that pair a specific casting or forging defect signature with established qualification methods.