1521939

Information

• Patent Grant
• 1521939

• References
• Source

• Patent Number

  1,521,939

• Date Filed

  Not available

• Date Issued

  Tuesday, January 6, 1925
  100 years ago

• CPC

  • B23G1/06 - specially adapted for making conical screws

• US Classifications

  • 470 - Threaded, headed fastener, or washer making: process and apparatus