Methods and apparatus for making and using tools, for example concrete cutting blades. The tool includes a first layer and a second layer that are oppositely disposed. The first and second layers include working surfaces that support at least one working element when the working element is applied to a work piece. Additionally, an intermediate structure is included between the first and second layers. The intermediate structure can include a plurality of components extending in the area between the structural surfaces and the working surfaces.

A system, a method and a cutting apparatus may use a bit to cut an object. The apparatus may have a bit connected to a cutting block on a cutting apparatus. The cutting apparatus may rotate about the object while the bit may advance into the object to cut the object. The cutting apparatus may have another bit located opposite to the bit to bevel an edge of the object. The cutting system may reduce point loads and/or provide an equalized load. The cutting system may reduce tool pressures when cutting a pipe and may provide extended tool and/or bit life.

A reciprocating saw blade that includes an elongated blade body defining an inner end and a distal end, a cutting edge located on one side of the blade body and extending between the inner and distal ends thereof and a tang located at the inner end of the blade body. The tang projects from the blade body at an acute angle of at least about 3° relative to a line tangent to an inner end of the cutting edge. The cutting edge includes a portion defining a substantially curved contour and optionally can include at least one further portion defining a non-curved contour.

A reciprocating saw blade including a body, an attachment portion, a cutting portion formed on the body including a plurality of cutting teeth, and a plunge point for initiating a plunge cut including a plunge tooth and a leading gullet between the plunge tooth and a first tooth of the plurality of cutting teeth. A first angle of the rake face of the plunge tooth is measured through the plunge tooth. A second angle of the rake face of the first cutting tooth is measured through the first cutting tooth. One of the first angle and the second angle is greater than 90 degrees and the other is less than 90 degrees. At least the first cutting tooth is set. The rake face defining the first angle is spaced from the rake face defining the second angle by a distance greater than the pitch of the plurality of cutting teeth.

A saw blade includes a body having a thickness, an attachment portion formed on the body, and a plurality of cutting teeth formed on the body. The attachment portion is configured to connect the saw blade to a power tool. Each cutting tooth of the plurality of cutting teeth includes a tip defining a plane that extends along the thickness of the body, a rake face extending from the tip, and a relief face extending from the tip opposite the rake face. A first cutting tooth of the plurality of cutting teeth is set in a first direction relative to the body. A second cutting tooth of the plurality of cutting teeth is set in a second direction opposite the first direction relative to the body. The planes defined by the tips of the first and second cutting teeth are generally parallel.

A saw blade blank includes a body having an edge and an attachment portion formed on the body. The attachment portion is configured to connect to a power tool. A first portion of the edge is set in a first direction relative to the body. A second portion of the edge is set in a second direction opposite the first direction relative to the body. No cutting teeth are formed on the edge of the body.

A reciprocating saw blade includes a body defining a longitudinal axis. The blade includes a cutting portion having a plurality of cutting teeth. Each cutting tooth includes a protrusion and a tip spaced a first distance from the protrusion. The tip of a first cutting tooth is spaced a pitch distance from the tip of an adjacent second cutting tooth. A gullet is defined between the tip of the first cutting tooth and the protrusion of the adjacent second cutting tooth. The tip of a respective cutting tooth is spaced a tip height distance from a base of the gullet. An apex of the protrusion is spaced a protrusion height distance from the base of the gullet. The protrusion height distance is 65% to 68% of the tip height distance. The first distance is 40% to 77% of the pitch distance.

A method of manufacturing a reciprocating saw blade includes forming a body with a shank end configured to secure the blade with a reciprocating saw, a plunging end configured to enter a workpiece, and a cutting edge and opposite back edge extending between the shank end and the plunging end. The cutting edge is formed to include a plurality of teeth arranged in a repeating pattern that includes left set teeth and right set teeth, the plurality of additional teeth being substantially the same size as each other and as the third tooth, wherein the plurality of additional gullets are substantially the same size as each other, and wherein the enlarged first gullet is longer in an axial direction than each of the plurality of additional gullets.

A reciprocating saw blade including a body, an attachment portion, a cutting portion formed on the body including a plurality of cutting teeth, and a plunge point for initiating a plunge cut including a plunge tooth and a leading gullet between the plunge tooth and a first tooth of the plurality of cutting teeth. A first angle of the rake face of the plunge tooth is measured through the plunge tooth. A second angle of the rake face of the first cutting tooth is measured through the first cutting tooth. One of the first angle and the second angle is greater than 90 degrees and the other is less than 90 degrees. At least the first cutting tooth is set. The rake face defining the first angle is spaced from the rake face defining the second angle by a distance greater than the pitch of the plurality of cutting teeth.