The invention relates to a rotary tool (1; 101; 201; 301; 401) for cutting large inside diameters at the outer circumference (2) of which at least one cutting edge (4; 104; 204) is arranged, comprising a support structure (10; 110; 210; 310; 410) which includes a supporting area (14; 114; 214) which indirectly or directly supports the cutting edge (4; 104; 204), and comprising a chucking portion (24; 124; 224; 324; 424) for coupling to a tool holder, wherein the support structure (10; 110; 210; 310; 410) is designed in light-weight construction and the area (14; 114; 214) of the support structure (10; 110; 210; 310; 410) indirectly or directly supporting the cutting edge (4; 104; 204) is limited regarding thermal expansion by a corset structure (12; 112; 212; 312; 412).

A core support system includes a support structure. The support structure includes a frame and a support member having a saturatable engagement layer disposed over the frame. A method of machining a core material includes applying a fluid to an engagement layer of a support structure and saturating the engagement layer with the fluid, disposing a core material on the engagement layer, causing the fluid to freeze to secure to the core material to the support structure, machining the core material, melting the frozen fluid to release the core material from the support structure, and removing the core material from the engagement layer.

A coated tool may include a base member having a first surface and a coating layer located on the first surface. The coating layer may have a first layer and a second layer. The first layer may be located on the first surface, and the first layer may include aluminum oxide. The second layer may be contactedly located on the first layer, and the second layer may include a titanium compound. In a cross section orthogonal to the first surface, the first layer may include a first projection protruding toward the second layer and a first recess located on the first projection. The second layer may include a second recess engaged with the first projection and a second projection engaged with the first recess.

A rotary cutting tool includes a main body and a shank. The main body has a tip end. The shank is continuous with the main body on the side opposite to the tip end. The main body is provided with a first cutting edge having a positive twist angle, and a second cutting edge having a negative twist angle and separated from the first cutting edge. Each of the first cutting edge and the second cutting edge extends continuously from the tip end to the shank.

An end mill for milling composite materials, for example, fiber-reinforced plastics, having a defined rotating direction, a shank and a cutting part that extends from a shank-side end up to a frontal end and in a front length region adjoining the frontal end of the cutting part, has a plurality of first circumferential cutters running with a positive helix angle, each of which adjoins a first groove running with a positive helix angle, and in a rear length region adjoining the shank-side end of the cutting part, has a plurality of second circumferential cutters running with a negative helix angle, each of which adjoins a second groove running with a negative helix angle. At least a part of the first circumferential cutters in the front length region, and at least a part of the second circumferential cutters in the rear length region, are each divided into cutting segments.

A rotary tool may include a main body having a circular columnar body, including a rotation axis and extending from a first end to a second end. The main body may include first flutes, second flutes, a first cutting edge, and a second cutting edge. The first flutes may have a helix angle 1 and the second flutes a reverse helix angle 2. The first cutting edge may be located on a ridge line where the outer periphery of the main body intersects with the first flutes and the second cutting edge at a ridge line where the outer periphery of the main body intersects with the second flutes. The 2 may be larger than the 1, m5, mn3, and m and n are coprime numbers, where m is the number of the first flutes and n is the number of the second flutes.

An end mill includes an end mill body having a bar-shape extending along a rotation axis and including a first end and a second end, a side surface, a first end cutting edge, a second end cutting edge, a first peripheral cutting edge extending from the first end cutting edge, and a second peripheral cutting edge extending from the second end cutting edge. In which, L2 is smaller than L1, where L1 is a distance from the rotation axis to the first peripheral cutting edge, and L2 is a distance from the rotation axis to the second peripheral cutting edge in a cross section orthogonal to the rotation axis. And 2 is greater than 1, where 1 is a rake angle of the first peripheral cutting edge, and 2 is a rake angle of the second peripheral cutting edge.

An orbital drill includes a drilling portion, a shank portion, and a neck portion between the drilling portion and the shank portion. The drilling portion includes one or more right-handed spiral flutes with cutting edges having a positive axial rake angle for positive cutting action while orbiting into a material. The right-handed spiral flutes have a positive radial and axial rake angle. The drilling portion also includes one or more left-handed spiral flutes located rearward of the one or more right-handed spiral flutes with cutting edges having a positive axial and radial rake angle for positive cutting action while orbiting back out of the material and removing any material left in the hole, thereby eliminating a separate reaming operation. A method of machining a workpiece using the orbital drill is also disclosed.

In an aspect, a rotating tool includes a main body having a rod shape and extending along a rotation axis. The main body includes a first end, a second end, a twisted cutting edge located at a side of the first end, a twisted flute, a reverse twisted cutting edge located closer to the second end than the twisted cutting edge, and a reverse twisted flute. The reverse twisted flute is connected to the twisted flute. The twisted cutting edge includes a first part having a length from the rotation axis decreasing as approaching toward the second end.

The present invention provides a material for built up edge formation having a resin block containing a high molecular weight compound having a weight average molecular weight of 510.sup.4 or higher and 110.sup.6 or lower, a medium molecular weight compound having a weight average molecular weight of 110.sup.3 or higher and lower than 510.sup.4, and a carbon.