B28D WORKING STONE OR STONE-LIKE MATERIALS
Introduced: September 1968
Description
B28D covers machines and methods for processing natural stone and stone-like materials, including cutting, grinding, polishing, shaping, and finishing operations. This subclass encompasses equipment such as stone saws, grinding mills, chisels, and automated machinery designed specifically for quarrying, dressing, and fabricating stone products into finished components or architectural elements. The classification includes both hand tools and industrial apparatus, as well as techniques for working materials such as granite, marble, limestone, slate, and synthetic stone composites, but excludes cement and clay processing, which are addressed in related subclasses.
IPC and CPC are identically structured here. All 4 subcodes exist in both systems.
4 shared codes have differing titles between IPC and CPC.
Child Classifications
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- B28D 1/00 Working stone or stone-like materials, e.g. brick, concrete , not provided for elsewhere; Machines, devices, tools therefor (fine working of gems, jewels, crystals B28D5/00; working by grinding or polishing B24; devices or means for dressing or conditioning abrasive surfaces B24B53/00) +4 CPC IPC+CPC Available in IPC and CPC
- B28D 3/00 Dressing mill discs or rollers (dressing the tools of sawing machines or sawing devices B23D63/00; treating the cutting members of cutting machines to facilitate cutting B26D7/08) +1 CPC IPC+CPC Available in IPC and CPC
- B28D 5/00 Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor (working by grinding or polishing B24; for artistic purposes B44B) +2 CPC IPC+CPC Available in IPC and CPC
- B28D 7/00 Accessories specially adapted for use with machines or devices of the preceding groups +1 CPC IPC+CPC Available in IPC and CPC
Top Applicants
Top Applicants (IPC)
Class B28,2013–2023, worldwide · Source: EPO PATSTAT
- MITSUBOSHI DIAMOND INDUSTRIAL COMPANY 868
- QINGDAO GAOCE TECHNOLOGY COMPANY 678
- DISCO CORPORATION JP 500
- ZHOU ZHAODI 500
- MITSUBOSHI DIAMOND INDUSTRIAL COMPANY JP 456
- HILTI LI 455
- CORNING US 407
- UNITED STATES GYPSUM COMPANY US 375
- ZHENGZHOU YUAN DONG REFRACTORIES COMPANY 370
- HUNAN SANY KUAIERJU RESIDENTIAL INDUSTRY COMPANY 351
Top Applicants (CPC)
Class B28,2013–2023, worldwide · Source: EPO PATSTAT
- DISCO CORPORATION JP 1,471
- HILTI LI 575
- CORNING US 544
- MITSUBOSHI DIAMOND INDUSTRIAL COMPANY JP 518
- UNITED STATES GYPSUM COMPANY US 485
- DISCO ABRASIVE SYSTEM 459
- GE (GENERAL ELECTRIC COMPANY) US 454
- MITSUBOSHI DIAMOND INDUSTRIAL COMPANY 439
- DISCO CORPORATION 403
- NGK INSULATORS JP 308