Disclosed is a thread chase or tap capable of being inserted past damaged threads of a female threaded coupling and then rotated back to repair the damaged threads. The thread chase can be selectively expanded to engage chase blocks having cutting teeth against threads. Thereafter, a user can rotate the thread chase in a direction sufficient to cause the thread chase to move axially out of the female threaded coupling. Upon doing so, the chase blocks can be pushed outwardly and engage undamaged threads, and rotated so as to move upward and repair damaged threads.

An insert portion (3) of a thread mill (1A) is fixed to a leading end portion of a body (2A) using screws (8). The insert portion (3) is configured by overlaying an insert (4) for finish machining and an insert (5) for rough machining. On respective mating faces of the inserts (4, 5), convex portions and concave portions of the mating face of the insert (4) are overlaid with concave portions and convex portions of the mating face of the insert (5). The thread mill (1A) can cut a female screw in a hole formed in a workpiece by performing right-hand cut down-cut milling, for example. The inserts (4, 5) simultaneously cut an inner peripheral surface of the hole, and the rough machining and the finish machining can thus be performed in a single pass. By the convex portions and the concave portions of the respective mating faces of the inserts (4, 5) being overlaid with each other, the inserts (4, 5) partially overlap in their respective thickness directions. As a result, a protrusion length of the insert portion (3) can be shortened.

A cutting insert according to one aspect has a flat plate shape including a first main surface having a polygonal shape, a second main surface located opposite to the first main surface, and an outer peripheral surface located between the first main surface and the second main surface. The cutting insert includes a cutting portion located in regions including at least a corner portion of the first main surface, and a main body portion located in a region other than the corner portion. A thickness of the main body portion is larger than a thickness of the cutting portions, and the main body portion includes a recessed portion or a protruding portion located in the outer peripheral surface thereof.

A method of operating a thread milling machine includes securing a product in a securing mount proximate to the thread milling machine, the thread milling machine having a spindle; securing a combination tool to the spindle, the combination tool having a body and an insert, the body having a first end and a second end, the body defining a securing pocket, the insert secured proximate to the second end at a first side of the securing pocket, the second end attached to the spindle; and rotating the spindle.

A thread milling system includes a thread milling machine having a spindle; and a combination tool having a body and a reaming insert, the body having a first end and a second end, the body defining a securing pocket, the reaming insert secured proximate to the second end of the body and within the securing pocket, the second end of the body attached to the spindle.

Disclosed is a thread chase or tap capable of being inserted past damaged threads of a female threaded coupling and then rotated back to repair the damaged threads. The thread chase can be selectively expanded to engage chase blocks having cutting teeth against threads. Thereafter, a user can rotate the thread chase in a direction sufficient to cause the thread chase to move axially out of the female threaded coupling. Upon doing so, the chase blocks can be pushed outwardly and engage undamaged threads, and rotated so as to move upward and repair damaged threads.

A combination tool for a thread milling system includes: a tool mount configured to secure the combination tool on a thread milling machine of the thread milling system; a body connected to the tool mount, the body having a first end and a second end, the body defining a securing pocket; and a reaming insert secured proximate to the second end and within the securing pocket.

An insert portion (3) of a thread mill (1A) is fixed to a leading end portion of a body (2A) using screws (8). The insert portion (3) is configured by overlaying an insert (4) for finish machining and an insert (5) for rough machining. On respective mating faces of the inserts (4, 5), convex portions and concave portions of the mating face of the insert (4) are overlaid with concave portions and convex portions of the mating face of the insert (5). The thread mill (1A) can cut a female screw in a hole formed in a workpiece by performing right-hand cut down-cut milling, for example. The inserts (4, 5) simultaneously cut an inner peripheral surface of the hole, and the rough machining and the finish machining can thus be performed in a single pass. By the convex portions and the concave portions of the respective mating faces of the inserts (4, 5) being overlaid with each other, the inserts (4, 5) partially overlap in their respective thickness directions. As a result, a protrusion length of the insert portion (3) can be shortened.

A thread cutting drill tool for metal cutting includes a cutting section having an axially extending chip flute and land, and a plurality of axially spaced teeth. Each tooth has an axially forward facing front flank and an axially rearward facing rear flank, a radially outward facing crest connecting the front flank and the rear flank, and a cutting edge. The cutting edge includes a set of crest cutting edges, each crest cutting edge being formed by an intersection of the crest of one tooth with the chip flute. The cutting edges include a set of front finishing edges and a set of rear finishing edges. Each front finishing edge is formed by an intersection of the front flank of one tooth with the chip flute. Each rear finishing edge is formed by an intersection of the rear flank of a tooth with the chip flute.

A die stock comprising a holder, which is symmetrical to a centric holder longitudinal axis, wherein the holder has a plurality of receiving grooves each of which is configured for receiving a cutting insert and a clamping wedge, each of the receiving grooves extending from a first end face of the holder in the axial direction, the first end face running transversely to the axial direction, and wherein each of the receiving grooves extends from an inner side of the holder in a radial direction, the inner side facing toward the holder longitudinal axis. The die stock further comprises a plurality of cutting inserts, wherein each cutting insert has, on a front side that faces substantially toward the holder longitudinal axis, at least one cutting edge. The die stock further comprises a plurality of clamping wedges arranged detachably in the receiving grooves.