CPC Subgroup
E21D 20/003 Full Title
Setting anchoring-bolts (anchoring bolts for shafts, tunnels or galleries E21D21/00; means for anchoring structural elements or bulkheads specially adapted to foundation engineering E02D5/74; dowels or other devices fastened in walls or the like by inserting them in holes made therein for that purpose F16B13/00)
1 direct subcode
Child Classifications
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Top Applicants
Top 10 applicants by patent filingsfor class E21, 2013–2023, worldwide · Source: EPO PATSTAT
- HALLIBURTON ENERGY SERVICES GROUP US 27,652
- SAUDI ARABIAN OIL COMPANY SA 7,755
- PETROCHINA COMPANY 7,025
- BAKER HUGHES US 6,589
- SCHLUMBERGER TECHNOLOGY US 6,151
- SINOPEC (CHINA PETROCHEMICAL CORPORATION) 4,443
- SCHLUMBERGER TECHNOLOGY NL 4,255
- CNPC (CHINA NATIONAL PETROLEUM CORPORATION) 3,991
- SERVICES PETROLIERS SCHLUMBERGER FR 3,300
- SCHLUMBERGER CANADA CA 3,086