Hard facing for milled tooth rock bits

US4944774A · kind A · utility

Assignee

• SMITH INTERNATIONAL, INC. · US

Inventors

• Madapusi K. Keshavan · Sandy, US
• Lance D. Underwood · Cypress, US
• Naresh J. Kar · Westminster, US
• Thomas W. Oldham · Diemelstraße, US
• Cary A. Roth · Spring, US
• Brian J. Armstrong · Henry's Drive, US

Key dates

• Filing date: Mar 27, 1989
• Grant date: Jul 31, 1990
• Expiry date: Mar 27, 2009

Classification

• Technology area (CPC E): Fixed Constructions
• CPC primary: E21B10/50
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A hard facing for teeth on a milled tooth rock bit comprises at least 65% by weight of a mixture of tungsten carbide particles and a balance of steel bonding the carbide particles together and to the cutter cone of the rock bit. The tungsten carbide particle mixture comprises from 35% to 80%, and preferably from 65% to 80%, by weight 20 to 30 mesh cemented tungsten carbide, and from 20% to 65%, and preferably from 20% to 35% by weight 40 to 80 mesh single crystal monotungsten carbide.