Isothermal forging keeps the die and workpiece at the same elevated temperature throughout deformation, which slows heat loss and lets the material deform at a controlled, often very low strain rate -- the evidence base includes claims with strain rates at or below 0.01 s-1. Precision forging is a broader goal: producing a part close enough to final shape that machining allowance is minimal. The two overlap heavily in this dataset because isothermal control is one of the main ways manufacturers reliably hit precision-forging tolerances on difficult alloys like titanium and nickel superalloys. Not every precision-forged part uses isothermal dies, but nearly every isothermal forging claim in this corpus is aimed at a precision or near-net-shape outcome.

Filing is concentrated at the top of the ranked list: the leading assignee holds 16 of the 119 records in scope, and the five largest filers together account for 42.9% of all records. The next tier thins out quickly -- the tenth-ranked assignee holds only 3 records -- and a long tail of single-filing entrants makes up the rest of the 54 ranked companies. That shape is typical of a mature process-engineering field: a handful of aerospace and heavy-industry manufacturers hold the core process claims, while smaller suppliers and research institutes file narrow, part-specific variations.

Forging and hammering process claims (IPC class B21J) appear on 60.5% of the 119 records, making it the single most common classification in this dataset. Forged metal products (B21K) and alloy composition claims (C22C) each cover more than a third of records, and non-ferrous metal treatment (C22F) -- which typically covers post-forge heat treatment and microstructure control -- appears on 27.7%. Titanium alloys feature prominently among the most-cited records, reflecting their importance in aerospace forging where isothermal control is often required to manage their narrow processing windows.

Filings peaked in 2018 at 12 records and the tracked three-year window from 2021 (4 records) to 2024 (2 records) shows a 50% decline. That said, publication typically lags actual filing by around 18 months, so 2025 and 2026 numbers in this dataset are still incomplete and should not be read as a confirmed downward trend yet. The more reliable read is that filing activity has settled into a steadier, lower rate since the 2018 peak rather than continuing to expand, but a firm conclusion about the very latest years will need another filing cycle to publish.

The thinnest technology classes in this dataset are coating and surface deposition (C23C, 7.6% of 119 records) and powder metallurgy (B22F, 8.4%), both well below the 60.5% density of core forging-process claims. Combined claims that integrate a powder-metallurgy preform step or a coating-and-lubrication step with an isothermal forging cycle appear underrepresented relative to the crowded core. Co-assignee filing is also rare -- only three pairs appear across the whole dataset -- suggesting there has been little cross-company collaboration in these adjacent branches, which is often where claim density stays low the longest.