Patent Number: 7,100,712

Title: Method for hardfacing roller cone drill bit legs

Abstract: A roller cone drill bit includes a bit body adapted to be coupled to a drill string, at ne leg depending from the bit body, and a bearing journal on the at least one leg, wherein least one leg defines a shirttail portion at an end thereof. A method of manufacturing the cone drill bit includes assembling a roller cone onto the bearing journal on the at least one asking around the shirttail portion, and performing a spray cycle. The spray cycle includes ng the shirttail portion with hardfacing using a high pressure/high velocity oxygen fuel after the roller cone is assembled onto the bearing journal.

Inventors: Crowe; John Ramsay (Aberdeenshire, GB), Greig; Angus (Aberdeen, GB), Hamilton; Robert (Aberdeen, GB), Farquhar; Gary (Aberdeen, GB), Angus; Kevin (Aberdeen, GB)

Assignee: Smith International, Inc.

International Classification: E21B 10/50 (20060101)

Expiration Date: 9/05/02018