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DIFF Subgroup
G01N 3/40

Investigating hardness or rebound hardness

Introduced: September 1968

Full Title

Investigating strength properties of solid materials by application of mechanical stress > Investigating hardness or rebound hardness

Of 6 combined children, 5 exist in both systems.

1 codes are CPC-only extensions.

4 shared codes have differing titles between IPC and CPC.

Child Classifications

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  • G01N 3/405 CPC only CPC only
  • G01N 3/48 by performing impressions under impulsive load by indentors, e.g. falling ball (G01N3/54 takes precedence) IPC+CPC Available in IPC and CPC
  • G01N 3/50 by measuring rolling friction, e.g. by rocking pendulum (G01N3/54 takes precedence) IPC+CPC Available in IPC and CPC
  • G01N 3/52 by measuring extent of rebound of a striking body (G01N3/54 takes precedence) IPC+CPC Available in IPC and CPC
  • G01N 3/54 Performing tests at high or low temperatures IPC+CPC Available in IPC and CPC

Top Applicants

Top Applicants (IPC)

Class G01,2013–2023, worldwide · Source: EPO PATSTAT

  1. SGCC(STATE GRID CORPORATION OF CHINA) 41,447
  2. CHINESE ACADEMY OF SCIENCES 32,952
  3. ROBERT BOSCH DE 16,470
  4. SAMSUNG ELECTRONICS COMPANY KR 10,052
  5. SINOPEC (CHINA PETROCHEMICAL CORPORATION) 9,573
  6. ZHEJIANG UNIVERSITY 9,529
  7. GUANGDONG POWER GRID CORPORATION 8,615
  8. TSINGHUA UNIVERSITY 7,805
  9. HALLIBURTON ENERGY SERVICES GROUP US 7,796
  10. QUALCOMM US 7,171

Top Applicants (CPC)

Class G01,2013–2023, worldwide · Source: EPO PATSTAT

  1. CHINESE ACADEMY OF SCIENCES 21,460
  2. ROBERT BOSCH DE 17,801
  3. SGCC(STATE GRID CORPORATION OF CHINA) 17,347
  4. SAMSUNG ELECTRONICS COMPANY KR 13,192
  5. QUALCOMM US 9,900
  6. HALLIBURTON ENERGY SERVICES GROUP US 9,742
  7. PHILIPS ELECTRONICS NL 7,249
  8. MITSUBISHI ELECTRIC CORPORATION JP 6,503
  9. ZHEJIANG UNIVERSITY 6,414
  10. DENSO CORPORATION JP 6,382