The invention relates to a method for preparing the surface of a substrate (100) for the purpose of accepting and holding a coating sprayed by a plasma torch. Said method includes a machining phase and is characterized that it includes the following phases: producing, by means of a machining tool (200), at least one groove having at least one angled edge; offsetting the tool (200) by moving the tool relative to the surface of the substrate (100) in a direction perpendicular to the longitudinal axis of the groove and along a path shorter than the projected length of the angled edge; and using said tool (200) on the angled edge of the groove such as to subject said edge to stress and create another offset groove, and so on and so forth, such that the tool (200) irreversibly changes the shape of the ribs (111, 112, 113, 114) finally obtained between each groove, and said ribs adopt undercut surfaces.

A milling apparatus has a housing, a drive shaft extending along and rotatable about an axis in the housing and an axially compressible and radially expansible washer stack on the front end of the drive shaft. A tool is held by the on the shaft. A bolt projects radially in a slot through the shaft and is limitedly axially displaceable in the shaft. An actuator element shiftable axially in the passage projects axially forward out of the drive shaft and is fixed in the bolt. A clamping assembly axially compresses and radially expands the stack so as to lock the tool to the drive shaft. A spring assembly is braced axially forward against the housing and axially rearward against the bolt. A piston axially displaceable on the drive shaft in the housing bears axially forward on the bolt.

A milling tool is disclosed. The milling tool may include an elongated body having a longitudinal axis and a plurality of cutting inserts. The cutting inserts may each have a cutting edge and a cutting radius and be coupled to the body and spaced along the longitudinal axis. One or more of the plurality of cutting inserts may be adjustable (e.g., mechanically adjustable) between first and second cutting radii. A difference between the first and second cutting radii may be at least 10 m. The milling tool may include cutting inserts having a plurality of different cutting radii. The milling tool may be configured to have a length that spans an entire height of an engine bore. The cutting inserts having different radii may compensate for dimensional errors in an engine bore diameter that occur when milling a deep pocket.

A method of milling an engine bore is disclosed. The method may include inserting a milling tool having a plurality of cutting edges along a longitudinal axis into an engine bore, rotating the milling tool about the longitudinal axis and moving the milling tool around a perimeter of the engine bore to remove material from the engine bore, and rough honing the bore. The milling may generate a tapered bore (e.g., frustoconical). The rough honing process may increase a minimum diameter of the tapered bore by at least 60 m. A total time of the milling and honing process may be less than 60 seconds. In one embodiment, the honing step may include using a grit size of at least 200 m and/or using a honing force of at least 200 kgf. The method may reduce the cycle time and tooling requirements of forming engine bores.

A replaceable head cutting tool increases the strength of engagement between a tool body and a coupling member without causing damage. A cylindrical mounting unit of the coupling member which is made of a metal having hardness lower than the hardness of the tool body, is inserted into a mounting hole having a concave portion formed on the inner surface of the tool body. The mounting unit is plastically deformed so as to increase in diameter, and the outer peripheral surface of the mounting unit contacts the inner peripheral surface of the mounting hole and is engaged with the concave portion which includes a first wall surface that is inclined toward the outer peripheral side as it moves in an insertion direction of the mounting unit, and a second wall surface that is inclined toward the inner peripheral side as it moves in the insertion direction.

A cutting tool system may include a tool body, a flexible internal pressure chamber, and at least one cutting edge. The flexible internal pressure chamber may be disposed within the tool body. The at least one cutting edge may be attached to the tool body. The flexible internal pressure chamber may be configured to elastically deform, due to pressure within the flexible internal pressure chamber, which in turn may deform the tool body, which in turn may change a position of the at least one cutting edge attached to the tool body.