A milling method includes moving a milling tool having at least two axially spaced apart sets of cutting inserts to an axial position within a bore in a material and rotating the milling tool about a longitudinal axis. The method further includes initiating contact between the milling tool and a wall of the bore in a region of the wall having a least amount of material at the axial position. The method further includes moving the milling tool around a perimeter of the bore.

A milling method includes moving a milling tool having at least two axially spaced apart sets of cutting inserts to an axial position within a bore in a material and rotating the milling tool about a longitudinal axis. The method further includes initiating contact between the milling tool and a wall of the bore in a region of the wall having a least amount of material at the axial position. The method further includes moving the milling tool around a perimeter of the bore.

A method for manufacturing a cylinder head includes: preparing a cylinder head casting having an intake passage, an exhaust passage, and a combustion chamber by casting using a mold and a plurality of cores; machining an intake port, an intake valve seat, an intake valve guide bore, an exhaust port, an exhaust valve seat, and an exhaust valve guide bore in the cylinder head casting by a first cylindrical tool; and forming a tapered surface on a portion of edge of the intake port by a second cylindrical tool. In particular, the second cylindrical tool moves along a predetermined trajectory at the edge portion of the intake port and rotates around an axis simultaneously to machine the tapered surface.

A milling method includes moving a milling tool having at least two axially spaced apart sets of cutting inserts to an axial position within a bore in a material and rotating the milling tool about a longitudinal axis. The method further includes initiating contact between the milling tool and a wall of the bore in a region of the wall having a least amount of material at the axial position. The method further includes moving the milling tool around a perimeter of the bore.

A milling method includes moving a milling tool having at least two axially spaced apart sets of cutting inserts to an axial position within a bore in a material and rotating the milling tool about a longitudinal axis. The method further includes initiating contact between the milling tool and a wall of the bore in a region of the wall having a least amount of material at the axial position. The method further includes moving the milling tool around a perimeter of the bore.

Milling tools and methods are disclosed. The method may include moving a milling tool having at least two axially spaced apart sets of cutting inserts to an axial position within a bore in a material and rotating the milling tool about a longitudinal axis. Contact between the milling tool and a wall of the bore may be initiated in a region of the wall having a least amount of material at the axial position. The milling tool may include a tool shaft having a longitudinal axis, a first set of radially spaced cutting inserts coupled to the tool shaft, and a directly adjacent second set of radially spaced cutting inserts coupled to the tool shaft and spaced from the first set of cutting inserts along the longitudinal axis. The first and second sets of cutting inserts may be staggered from each other by at least 10 degrees.

Milling tools and methods are disclosed. The method may include moving a milling tool having at least two axially spaced apart sets of cutting inserts to an axial position within a bore in a material and rotating the milling tool about a longitudinal axis. Contact between the milling tool and a wall of the bore may be initiated in a region of the wall having a least amount of material at the axial position. The milling tool may include a tool shaft having a longitudinal axis, a first set of radially spaced cutting inserts coupled to the tool shaft, and a directly adjacent second set of radially spaced cutting inserts coupled to the tool shaft and spaced from the first set of cutting inserts along the longitudinal axis. The first and second sets of cutting inserts may be staggered from each other by at least 10 degrees.

An automatic milling machine mills a gasket. The automatic milling machine controls the position of a cutter head relative a table. The automatic milling machine rotates the gasket with a motor. Parameters of the motor are monitored to determine the amount of rotation of the gasket.

A valve seat processing machine configured to process a valve seat in a valve device including a valve body portion which forms a flow passage of fluid and a valve drive portion which drives a valve element capable of tightly engaging with the valve seat includes: a base portion attached to the valve body portion; a main body portion movable relative to the base portion; a support portion movable relative to the main body portion in a drive direction of the valve element; a main spindle rotatable relative to the support portion about an axis parallel to the drive direction of the valve element; a tool holder configured to hold a tool for processing the valve seat and movable relative to the main spindle in a direction intersecting the drive direction of the valve element; and a controller configured to control movement of the support portion and the tool holder.

A sealing surface processing machine cuts an attachment surface of a seal member in a valve main body. The machine includes a pedestal attached to the valve main body; a main body movably supported on the pedestal; a tool holder configured to hold a tool for processing the attachment surface; a rotating part configured to rotate the tool holder around an axis parallel to a movement direction of a valve body; a first moving part configured to move the tool holder along a first direction along which the valve body moves; a second moving part configured to move the tool holder along a second direction intersecting with the movement direction of the valve body; a first adjustment device configured to adjust a position of the main body in the first direction; and a second adjustment device configured to adjust a position of the main body in the second direction.