Press hardening, also called hot stamping or hot forming, heats a steel blank to austenitizing temperature and then forms it inside a cooled die, so the part quenches into an ultra-high-strength martensitic structure as it is shaped. Cold stamping forms the metal at or near room temperature and relies on the sheet’s existing microstructure for strength, which limits how thin and strong a part can be simultaneously. The patent record in this space concentrates heavily on heat treatment (C21D, 31.6% of records) and alloy composition (C22C, 27.6%), reflecting how much of the innovation sits in controlling the thermal cycle rather than the mechanical forming step itself.

The field has one clear leader holding 178 records, well ahead of the fifth-placed assignee at 95 and the tenth-placed assignee at 39. The top 5 assignees combined account for 24.6% of all 2,786 records in scope, and the top 10 for 32.7%, which leaves the majority of filings spread across a long tail of smaller and single-filing entrants. This structure suggests that while a handful of steelmakers and automotive suppliers hold meaningful blocking positions, the field is not so consolidated that a well-drafted new claim has no room.

Filing activity peaked at 264 records in 2019 and has since eased, falling -18% from 114 records in 2021 to 94 in 2024, the most recent year that can be treated as a complete data point. It would be a mistake to read the lower raw counts in 2025 and 2026 as continued decline, because patent publication typically lags the actual filing date by around 18 months, so the newest years are still being filled in as pending applications publish. The safest read is that filing has cooled modestly from its 2019 peak, not that the technology is losing investment.