A method is disclosed for forming a drill bit structure to which a cutting element is to be affixed. The method includes applying a layer of hardfacing material to a basic bit structure, removing the layer of hardfacing material in a location to which the cutting element is to be affixed, and forming an attachment structure at the location. In one embodiment, the removing is performed by electrode discharge machining. In one embodiment, the basic bit structure is a roller cone, and the cutting e...

A method of making a threaded ring (24) into two (2) semicircular portions (30, 32) for fitting within a groove (19) on a journal (12) of a drill bit (10) to retain a roller cutter (20) thereon. The ring (24) is first formed with screw threads (26) about an oversized outer diameter and then cut into two semicircular portions (30, 32). The amount of the oversized outer diameter compensates for the thickness of the material removed by the cut as shown at W. If the thickness of the cut exceeds a ce...

A method for use in designing rotary drill bits comprises determining locations in which cutters are to be provided, determining likely wear rates for cutters positioned at those locations, and using the likely wear rates to chose between relatively high and relatively low wear rate cutters for each location. The cutters all have substantially the same impact toughness.

A method of manufacturing a bit body, other drilling-related component, or other article of manufacture, including fabricating a particulate-based matrix and infiltrating the particulate-based matrix with a binder that includes cobalt or iron. The binder may be a cobalt alloy or an iron alloy. The particulate-based matrix may be disposed within a non-graphite mold. The particulate-based matrix and binder are placed within an induction coil and an alternating current is applied to the induction c...

The preferred embodiments are directed toward methods and apparatus for manufacturing components for earth-boring drill bits. In the preferred embodiments, a portion of the component is coated and the component is exposed to a carbon-rich environment at an elevated temperature. During this exposure, some portions of the component are not coated. The preferred embodiments further comprise coating the areas that were exposed to the carbon-rich environment and exposing the component to an elevated ...

A method of forming a PDC drilling bit including the steps of imposing a side drilling direction on the bit, determining a total bit side force acting on the bit, computing a walk angle between the total side force and the side drilling direction, and modifying a configuration of cutters on the profile of the bit so as to change the walk angle to a desired angle. The step of determining a total side force includes the steps of determining a normal side force of the bit, computing a total cutter ...

A matrix drill bit and method of manufacturing a matrix bit body from a composite of matrix materials is disclosed. Two or more different types of matrix materials may be used to form a composite matrix bit body. A first matrix material may be selected to provide optimum fracture resistance (toughness) and optimum erosion, abrasion and wear resistance for portions of a matrix bit body such as cutter sockets, cutting structures, blades, junk slots and other portions of the bit body associated wit...

A connection rod (1) for rock drilling includes a first rod part (2) whidh has an external thread (4) provided at one end thereof, wherein the end of the rod opposite to the one end includes an end portion (6) which carries an internal thread (5), wherein the end portion (6) is joind to the first rod part (2) by friction welding and wherein the end portion (6) has been heat treated prior to being joined to the first rod part (2). The invention also relates to a method of producing such a connect...

A shaped insert that includes a top portion, and a grip length, wherein the grip length is modified to have a non-uniform cross sectional area is disclosed. In another case, a shaped insert includes a top portion, and a grip length, wherein the grip length is modified such that the insert is non-cylindrical. In another case, a shaped insert includes a top portion, and a grip length, wherein the grip length is coated in a non-uniform manner.

Roller cone drill bits may be formed with cutting elements and cutting structures having cutting element profile angles selected to minimize cone wobble and improve life of associated bearings and seals. Normal force axes of the cutting elements may intersect with each other as a force center. Crest points of the cutting elements may be disposed on one or more circles extending from the associated force center.