3856357

Information

• Patent Grant
• 3856357

• References
• Source

• Patent Number

  3,856,357

• Date Filed

  Not available

• Date Issued

  Tuesday, December 24, 1974
  50 years ago

• CPC

  • E21C27/10 - by both slitting and breaking-down

• US Classifications

  • 299 - Mining or in situ disintegration of hard material
  • 175 - Boring or penetrating the earth