Threading tap for cutting threads in blind holes and methods of its manufacture
AssigneeSandvik Intellectual Property AB
InventorsGiovanna Malagnino, Roberto Troilo
Life of this patent
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Abstract
A threading tap for cutting threads in blind holes includes an elongated body with a central axis, the body having at a rear end a connector portion, and having at a front end a threading portion. The threading portion is provided with at least one helical thread-cutting structure and interconnected flank portions defining at least one helical flute which interrupts the helical thread cutting structure. The flank portions present exposed surfaces that are steam tempered. The rest of the tap is coated by PVD.
Claims21
A threading tap for cutting threads in blind holes, comprising an elongated body defining an axis of rotation and including axial front and rear end regions, the front end region including a threading portion having teeth defining a helical thread-cutting structure, and at least one helical flute formed in an outer periphery of the body and interrupting the thread-cutting structure, the threaded portion being coated with a PVD coating and the at least one flute comprising interconnected flanks having exposed surfaces that are steam tempered but not coated with the said PVD coating, wherein a helix angle of the flute relative to the axis is between 46° and 55°.
A threading tap for cutting threads in blind holes, comprising an elongated body defining an axis of rotation and including axial front and rear end regions, the front end region including a threading portion having teeth defining a helical thread-cutting structure, and at least one helical flute formed in an outer periphery of the body and interrupting the thread-cutting structure, the threaded portion being coated with a PVD coating and the at least one flute comprising interconnected flanks having exposed surfaces that are steam tempered but not coated with the said PVD coating, wherein a helix angle of the flute relative to the axis is between 46° and 55° wherein the body comprises high-speed steel.
A method of manufacturing a threading tap suitable for cutting threads in blind holes, including the following steps:
- A) selecting a blank comprising an elongated body defining an axis of rotation and including axial front and rear regions;
- B) forming at least one helical flute in an outer periphery of the body, the at least one flute comprising interconnected flanks having exposed surfaces;
- and
- C) steam tempering only the exposed surfaces of the flute, wherein the at least one flute is formed such that a helex angle of the flute relative to the axis is between 46° and 55°.
Dependencies are inferred from the claim text.