A ball end mill according to the present invention includes an end mill body which is formed in a shaft shape, a plurality of convex arcuate end cutting edges which are disposed on a tip portion of the end mill body at intervals around an axis and form a hemispherical shape such that a rotational locus around the axis has a center on the axis, and a plurality of gashes which are respectively disposed to be adjacent to the plurality of end cutting edges in an end mill rotation direction around the axis. The plurality of end cutting edges includes a first end cutting edge longest among the plurality of end cutting edges, a second end cutting edge which is adjacent to the first end cutting edge in the end mill rotation direction and a third end cutting edge which is adjacent to the second end cutting edge in the end mill rotation direction.

An end mill machining apparatus, a CAM apparatus, an NC program, and a machining method which suppress regenerative self-excited vibration and mode-coupling self-excited vibration. An end mill machining apparatus includes an end mill, and a control section for controlling the end mill. The ratio of the protrusion length of the end mill to the diameter of the end mill falls within a range of 5 to 50. The end mill is a variable pitch, uniform helix type or a variable helix type. The control section controls the end mill such that the contact angle between the end mill and a workpiece M1 during machining becomes equal to or smaller than a critical contact angle .sub.lim.

A golf club head and a method of manufacturing a golf club head are described herein. The golf club head comprises a club face with a face portion, and grooves positioned on the club face. The grooves each comprise a bottom, a first side wall adjacent the bottom, a second side wall adjacent the bottom, a first top radius adjacent the first side wall, and a second top radius adjacent the second side wall. The club face further comprises a second portion positioned between the face portion, and the first top radius and the second top radius. The second portion of the club face allows for the grooves to appear visually wider to a player, which can provide psychological effects to benefit performance, while still conforming to USGA groove widths standards.

A method for machining of ball tracks of an inner race of a constant velocity joint includes the step of providing a power skiving tool having a plurality of cutting members and a first axis of rotation and providing a work piece having an outer envelope surface extending along an axis of rotation. The first axis of rotation of the power skiving tool is arranged at a first distance from the axis of rotation of the work piece and oriented at a first angle. A first rotational speed to the power skiving tool and a second rotational speed to the work piece and a relative movement between the work piece and the power skiving tool, is applied such that the cutting members engage the outer envelope surface to machine the ball tracks. A cutting insert and a power skiving cutting tool are also provided.

A method for machining of ball tracks of an inner race of a constant velocity joint includes the step of providing a power skiving tool having a plurality of cutting members and a first axis of rotation and providing a work piece having an outer envelope surface extending along an axis of rotation. The first axis of rotation of the power skiving tool is arranged at a first distance from the axis of rotation of the work piece and oriented at a first angle. A first rotational speed to the power skiving tool and a second rotational speed to the work piece and a relative movement between the work piece and the power skiving tool, is applied such that the cutting members engage the outer envelope surface to machine the ball tracks. A cutting insert and a power skiving cutting tool are also provided.

An engine roller lifter for use in a valve train of an internal combustion engine according to one example of the present disclosure includes a body and a groove formed in the body. The body has an outer peripheral surface configured for sliding movement in a bore provided in the engine. The bore is supplied by an oil passage communicating therewith. The body defines an axial pocket that receives a plunger therein. The groove is inset from the outer peripheral surface and formed about only a portion of a circumference of the body. The groove defines a first end and a second end. Only a portion of the first and second ends overlap with the oil passage to regulate the amount of oil supplied to the groove from the oil passage.

An engine roller lifter for use in a valve train of an internal combustion engine according to one example of the present disclosure includes a body and a groove formed in the body. The body has an outer peripheral surface configured for sliding movement in a bore provided in the engine. The bore is supplied by an oil passage communicating therewith. The body defines an axial pocket that receives a plunger therein. The groove is inset from the outer peripheral surface and formed about only a portion of a circumference of the body. The groove defines a first end and a second end. Only a portion of the first and second ends overlap with the oil passage to regulate the amount of oil supplied to the groove from the oil passage.

A method for providing a dismantling groove in an element for a product to be assembled by a plurality of elements locked by a locking arrangement including a flexible tongue is disclosed. The method includes providing an insertion groove and a dismantling groove in the same element. The dismantling groove extends along the element between a first side and a second side and is configured for receiving the flexible tongue of the locking arrangement for locking the element to another element having a tongue groove. The dismantling groove is provided in the element such that it extends from the first side to the insertion groove and along a portion of the insertion groove, and is configured to receive a dismantling tool for dismantling the element from the other element. An element with an insertion groove and a dismantling groove is also disclosed.

A method for providing a dismantling groove in an element for a product to be assembled by a plurality of elements locked by a locking arrangement including a flexible tongue is disclosed. The method includes providing an insertion groove and a dismantling groove in the same element. The dismantling groove extends along the element between a first side and a second side and is configured for receiving the flexible tongue of the locking arrangement for locking the element to another element having a tongue groove. The dismantling groove is provided in the element such that it extends from the first side to the insertion groove and along a portion of the insertion groove, and is configured to receive a dismantling tool for dismantling the element from the other element. An element with an insertion groove and a dismantling groove is also disclosed.

Disclosed is a method for making a decorative groove between joint edges on a laminate floorboard. The floorboard includes an upper layer and an underlying layer. The method involves fixing the floorboard between at least one chain and at least one band, displacing the floorboard relative to a milling machine, and removing at least a part of the upper layer, so that a surface of the underlying layer is uncovered, by a tool that performs machining between the at least one chain. The surface of the underlying layer defines at least a portion of a visible width of the decorative groove.