Hole finishing tool and method of producing hole finished product

A hole finishing tool comprising:

• a reaming cutter having a first detaching structure in a back end side of the hole finishing tool, a first flow path for ejecting cutting oil being formed inside the reaming cutter, the first detaching structure including a first screw or coupler;
• a holder being more proximally positioned along an axis of elongation of the hole finishing tool than the reamer cutter, said holder having a second detaching structure in a tip side of the hole finishing tool, the second detaching structure being detached from and attached to the first detaching structure, a second flow path for supplying the cutting oil to the first flow path being formed inside the holder, the holder having a shank in the back end or proximal side of the hole finishing tool, the shank being held by a tool rotating device having a motor, the holder having a slider in the tip side of the hole finishing tool, the slider having no back taper, the second detaching structure including a second screw or coupler;
• and
• a positioning bush for inserting and sliding the slider, the positioning bush and slider being in a clearance fit relationship,
• wherein at least one of an outer surface of the slider and an inner surface of the positioning bush has a concave portion which is configured for storing lubrication oil by way of surface tension adhesion of the lubricating oil received within the concave portion as to be retained within the concave portion and to maintain clearance fit lubrication during sliding and/or rotation of the slider, and wherein the slider is either free of an outer surface discharge port or has one or more discharge ports for discharging a part of the cutting oil flowing through the second flow path for reducing friction between the positioning bush and the slider, and wherein, when the one or more discharge ports are present, a most proximally positioned one of said one or more discharge ports on the slider is retained within the bush in a most retreated position of the slider within the bush,
• wherein, at least at an interface region of the first and second detaching structures, the first and second flow paths are centrally located, with each extending along a central axis of the tool, and
• wherein, at least at the interface region, the concave portion of the slider is of a radial depth that is less than a length of a radius extending from the central axis of the tool to an exterior surface of the slider in which the concave portion is formed.

A hole finishing tool comprising:

• a reaming cutter having a first detaching structure in a back end side of the hole finishing tool, a first flow path for ejecting cutting oil being formed inside the reaming cutter, the first detaching structure including a first screw threaded region;
• and
• a holder having a second detaching structure in a tip side of the hole finishing tool, the second detaching structure being detached from and attached to the first detaching structure, a second flow path for supplying the cutting oil to the first flow path being formed inside the holder, the holder having a shank in the back end side of the hole finishing tool, the shank being held by a tool rotating device having a motor, the second detaching structure including a second screw threaded region;
• and
• a positioning bush,
• wherein the holder has a slider in the tip side of the hole finishing tool, the slider having no back taper, the slider being inserted into the positioning bush and slid inside the positioning bush in a clearance fit relationship, the slider having a concave portion which is configured for storing lubrication oil by way of surface tension adhesion of the lubricating oil received within the concave portion as to be retained within the concave portion and to maintain clearance fit lubrication during sliding and/or rotation of the slider, and wherein the first and second screw threaded regions include a female screw threaded section defining a reception recess, and a male screw threaded member featuring a first step down region extending axially away from a supporting one of said reamer cutter and holder and a second step down region extending axially away from the first step down region to a free end, and with the second step down region having a diameter smaller than the first step down region, and with the male screw threaded member being threadably secured within the reception recess such that the first step down region is positioned within the bushing upon full retraction of the reamer cutter into the bushing,
• wherein, at least at a threading interface region of the first and second detaching structures, the first and second flow paths are centrally located, with each extending along a central axis of the tool, and
• wherein, at least at the threading interface region, the concave portion of the slider is of a radial depth that is less than a length of a radius extending from the central axis of the tool to an exterior surface of the slider in which the concave portion is formed.