A tungsten-carbide-based hard material includes the following components: tungsten carbide with an average particle size of 0.1-1.3 μm; 1.0-5.0 wt. % (Co+Ni), with a ratio of Co/(Co+Ni) in wt. % of 0.4≤Co/(Co+Ni)≤0.95; 0.1-1.0 wt. % Cr, with a ratio of Cr to (Co+Ni) in wt. % of 0.05 Cr/(Co+Ni) 0.20; 0.01-0.3 wt. % Mo; and 0.02-0.45 wt. % Me, where Me represents one or more elements from the group Ta, Nb, Hf and Ti, preferably Ta and/or Nb; and wherein 0.01≤Me/(Co+Ni)≤0.13.

A circular saw blade includes a plurality of cutting teeth repeatedly alternating between a first set of cutting teeth and a second set of cutting teeth around the periphery of the saw blade. Each first set of cutting teeth includes at least two efficient cutting teeth, each second set of cutting teeth comprising at least one robust cutting tooth. Each first set of teeth and each second set of teeth are configured such that, if one tooth in the first set of teeth breaks, the chip load in the immediately following second set of teeth increases by less than approximately 45%.

A circular saw blade includes a plurality of cutting teeth repeatedly alternating between a first set of cutting teeth and a second set of cutting teeth around the periphery of the saw blade. Each first set of cutting teeth includes at least two efficient cutting teeth, each second set of cutting teeth comprising at least one robust cutting tooth. Each first set of teeth and each second set of teeth are configured such that, if one tooth in the first set of teeth breaks, the chip load in the immediately following second set of teeth increases by less than approximately 45%.

A circular saw blade includes a plurality of cutting teeth repeatedly alternating between a first set of cutting teeth and a second set of cutting teeth around the periphery of the saw blade. Each first set of cutting teeth includes at least two efficient cutting teeth, each second set of cutting teeth comprising at least ne robust cutting tooth. Each first set of teeth and each second set of teeth are configured such that, if one tooth in the first set of teeth breaks, the chip load in the immediately following second set of teeth increases by less than approximately 45%.

A circular saw blade includes a plurality of cutting teeth repeatedly alternating between a first set of cutting teeth and a second set of cutting teeth around the periphery of the saw blade. Each first set of cutting teeth includes at least two efficient cutting teeth, each second set of cutting teeth comprising at least ne robust cutting tooth. Each first set of teeth and each second set of teeth are configured such that, if one tooth in the first set of teeth breaks, the chip load in the immediately following second set of teeth increases by less than approximately 45%.

A circular saw blade comprising: a rigid central disk that is provided with a central pass-through hole adapted to be engaged by the machine-tool spindle; and a series of teeth that jut out from the periphery of the rigid central disk in a substantially radial direction, are suitably spaced along the periphery of the rigid central disk and have, on their front edge, a cutting insert; at least one of said teeth being provided with a plate-like protruding ridge or appendage that projects from the back of the tooth, towards the cutting insert of the following tooth, and is tapered towards its distal end; said protruding appendage and the front edge of the following tooth being shaped so as to form a substantially circular-shaped gullet in front of the following tooth.

A circular saw blade comprising: a rigid central disk that is provided with a central pass-through hole adapted to be engaged by the machine-tool spindle; and a series of teeth that jut out from the periphery of the rigid central disk in a substantially radial direction, are suitably spaced along the periphery of the rigid central disk and have, on their front edge, a cutting insert; at least one of said teeth being provided with a plate-like protruding ridge or appendage that projects from the back of the tooth, towards the cutting insert of the following tooth, and is tapered towards its distal end; said protruding appendage and the front edge of the following tooth being shaped so as to form a substantially circular-shaped gullet in front of the following tooth.

A long metal sheet is rolled in a width direction to form a hollow tube while being delivered. A seam appeared in a longitudinal direction of a tubular body is electrically welded to form an electric-resistance-welded tube. The electric-resistance-welded tube is cut in a predetermined size by a circular saw cutting machine which travels in synchronicity with the electric-resistance-welded tube during its production process. A weld bead remains at the seam of the electric-resistance-welded tube so that the weld bead remained in the tube may be involved when the electric-resistance-welded tube is cut by the circular saw blade. Therefore, there is a problem to be solved that a significant load may be generated on a second rake face of the tip when the cutting tip of the circular saw blade bites debris in the tube, which may lead to the chipping or missing of the tips.

Solution to Problem

A circular saw blade has a plurality of cutting tips 10 joined at an outer circumference of a base metal. Each of the cutting tips 10 includes a first rake face 14 located at a front of the tip of the circular saw blade in a rotation direction of the circular saw blade, a flank 18 located in an outer circumferential direction of the circular saw blade, and a second rake face 22 adjacent to the first rake face 14 on a side of an axis of the circular saw blade. The center of the second rake face 22 is configured to project in the rotation direction of the circular saw blade.

A long metal sheet is rolled in a width direction to form a hollow tube while being delivered. A seam appeared in a longitudinal direction of a tubular body is electrically welded to form an electric-resistance-welded tube. The electric-resistance-welded tube is cut in a predetermined size by a circular saw cutting machine which travels in synchronicity with the electric-resistance-welded tube during its production process. A weld bead remains at the seam of the electric-resistance-welded tube so that the weld bead remained in the tube may be involved when the electric-resistance-welded tube is cut by the circular saw blade. Therefore, there is a problem to be solved that a significant load may be generated on a second rake face of the tip when the cutting tip of the circular saw blade bites debris in the tube, which may lead to the chipping or missing of the tips.

Solution to Problem

A circular saw blade has a plurality of cutting tips 10 joined at an outer circumference of a base metal. Each of the cutting tips 10 includes a first rake face 14 located at a front of the tip of the circular saw blade in a rotation direction of the circular saw blade, a flank 18 located in an outer circumferential direction of the circular saw blade, and a second rake face 22 adjacent to the first rake face 14 on a side of an axis of the circular saw blade. The center of the second rake face 22 is configured to project in the rotation direction of the circular saw blade.

A method for producing a drill ring for a core drill bit is disclosed. The method includes constructing at least two green parts from encapsulated diamond particles, the diamond particles being covered by a powder mixture. The green parts are formed into ring segments under the effect of pressure and the ring segments are annularly assembled and sintered under temperature action to form a continuous drill ring.