A thread tap includes a shaft and teeth. The shaft includes helical passages from the threading end to the base end of the shaft. Each passage opens through an aperture in the threading end. A second tap includes a cap and the shaft includes an axially extending passage. The cap is coupled to the threading end and at least partially defines apertures in fluid communication with the passage and the exterior of the tap. A third tap includes teeth spaced apart by a plurality of linear flutes. The shaft includes a central passage and a plurality of flute passages. Each flute passage extends radially outward from a common location in the central passage to a corresponding one of the flutes. The central passage is closed to a terminal end of the threading end.

A thread tap includes a shaft and teeth. The shaft includes helical passages from the threading end to the base end of the shaft. Each passage opens through an aperture in the threading end. A second tap includes a cap and the shaft includes an axially extending passage. The cap is coupled to the threading end and at least partially defines apertures in fluid communication with the passage and the exterior of the tap. A third tap includes teeth spaced apart by a plurality of linear flutes. The shaft includes a central passage and a plurality of flute passages. Each flute passage extends radially outward from a common location in the central passage to a corresponding one of the flutes. The central passage is closed to a terminal end of the threading end.

A thread tap includes a shaft and teeth. The shaft includes helical passages from the threading end to the base end of the shaft. Each passage opens through an aperture in the threading end. A second tap includes a cap and the shaft includes an axially extending passage. The cap is coupled to the threading end and at least partially defines apertures in fluid communication with the passage and the exterior of the tap. A third tap includes teeth spaced apart by a plurality of linear flutes. The shaft includes a central passage and a plurality of flute passages. Each flute passage extends radially outward from a common location in the central passage to a corresponding one of the flutes. The central passage is closed to a terminal end of the threading end.

A spiral flute tap includes a body having an axial forward end and an axial rearward end. The body has a cylindrical shank portion adjacent the axial rearward end, a threaded fluted portion adjacent the axial forward end, a non-threaded fluted portion between the cylindrical shank portion and the threaded fluted portion, and a central, longitudinal axis. The spiral flute tap further includes a plurality of helical flutes formed at a helix angle, HA, with respect to the central, longitudinal axis of the tap that continuously increases in magnitude in the threaded fluted portion. In other words, the lead of the plurality of helical flutes continuously decreases in magnitude in a rearward direction for a predetermined distance. In one example, the helix angle, HA, varies at a rate of between 0.5 degrees/mm to 4.0 degrees/mm. A method of making the spiral flute tap is also disclosed.

A spiral flute tap includes a body having an axial forward end and an axial rearward end. The body has a cylindrical shank portion adjacent the axial rearward end, a threaded fluted portion adjacent the axial forward end, a non-threaded fluted portion between the cylindrical shank portion and the threaded fluted portion, and a central, longitudinal axis. The spiral flute tap further includes a plurality of helical flutes formed at a helix angle, HA, with respect to the central, longitudinal axis of the tap that continuously increases in magnitude in the threaded fluted portion. In other words, the lead of the plurality of helical flutes continuously decreases in magnitude in a rearward direction for a predetermined distance. In one example, the helix angle, HA, varies at a rate of between 0.5 degrees/mm to 4.0 degrees/mm. A method of making the spiral flute tap is also disclosed.

A pipe-tapered-thread machining tap has a thread, four spiral flutes and four cutting edges that include a plurality of thread intersection portions at each of which a corresponding one of the four cutting edges intersects with the thread. The thread intersection portions of the cutting edges have four groups, such that each of the four groups has ones of the thread intersection portions that are portions of a corresponding one of the four cutting edges. Every two of the thread intersection portions of each of the four groups is removed, such that, in each of the four groups, at least one of the thread intersection portions that is removed and at least another one of the thread intersection portions that is not removed are alternately arranged in a direction in which a corresponding one of the four cutting edges extends.

A pipe-tapered-thread machining tap has a thread, four spiral flutes and four cutting edges that include a plurality of thread intersection portions at each of which a corresponding one of the four cutting edges intersects with the thread. The thread intersection portions of the cutting edges have four groups, such that each of the four groups has ones of the thread intersection portions that are portions of a corresponding one of the four cutting edges. Every two of the thread intersection portions of each of the four groups is removed, such that, in each of the four groups, at least one of the thread intersection portions that is removed and at least another one of the thread intersection portions that is not removed are alternately arranged in a direction in which a corresponding one of the four cutting edges extends.

An indexable cutting tool that allows for stable clamping of cutting inserts and prevents contact between head parts of fastening members and workpieces is provided. Recesses with a bottom are formed in an upper surface of the cutting insert. At least part of an inner wall surface of the recess is a curved surface bulged toward a center axis of the recess. When the recess is divided into four, first to fourth, regions by a first imaginary reference plane parallel to a rotation axis of a body and a second imaginary reference plane perpendicular to the rotation axis, the second region is located on a center side and on a proximal side of the body. A tapered surface of the fastening member makes contact with the curved surface within the second region. A center axis line of the fastening member is inclined such that the head part opposite from a distal end part is located closer to the center side and to the proximal side of the body than the distal end part.

A surface-coated cutting tool has a rake face and a flank face, and includes a base material and a coating formed on the base material. The base material has a cutting edge face connecting the rake face to the flank face. The coating includes an aluminum oxide layer containing a plurality of aluminum oxide crystal grains. The aluminum oxide layer includes: a first region made up of a region A on the rake face and a region B on the flank face; a second region on the rake face except for the region A; and a third region on the flank face except for the region B. The aluminum oxide layer satisfies a relation: ba>0.5, where a is an average value of TC(006) in the first region in texture coefficient TC(hkl), and b is an average value of TC(006) in the second or third region in texture coefficient TC(hkl).

An access device is provided for access to a fluid tank, especially a fluid tank of a ship. The access device includes a drill, a thread-forming unit, a hollow body with an external thread and a connection plate. The hollow body is provided with a valve.