Abstract: A hard machining process uses a cylindrical tool (21) of ceramic or other hard machining material of comparatively low cost that provides a circular cutting edge to be engaged in cutting relation with hardened workpiece (20) to be machined. As tool cutting edge wear occurs, the tool (21) is rotated through a small angle to bring into contact with the workpiece (20) a fresh portion of the cutting edge. It is not necessary to rotate that tool (21) sufficiently to effect replacement of the entire cutting edge portion in engagement with the tool. Sufficient angular movement of the tool is made to replace that of the cutting edge that has the greatest effect on the finish of the machined workpiece (20), which is the cutting location where the removed chip is thinnest.

Abstract: An improved static mixer is disclosed which is capable of efficient mixing and is of a construction which allows relatively inexpensive manufacture. A pair of flow channels are provided for respectively receiving the fluids to be mixed at respective ends thereof. The flow channels have at least one common wall element therebetween, the common wall element having an undulating shape which alternately enlarges and restricts one of the channels while simultaneously alternately restricting and enlarging the other of the channels in opposing relationship. The common wall has openings therein at about the peaks and valleys of the undulations. In operation, two fluids to be mixed are introduced to the respective flow channels. At each peak or valley of the undulating wall element, the opposing enlargement and restriction of the two channels causes a pressure difference and results in a cross flow through the openings in the common wall element.

Abstract: A grinding wheel is provided around the inside of its hole with a plurality of turns of an electrical conductor weaker in tension than the material of the wheel, the ends of which are brought out to terminals on the surface of the wheel. Incipient cracks in the wheel rupture the conductor, which is checked as desired with a continuity testing device.

Abstract: The specification discloses nucleating diamonds in the absence of an external container. Nickel and graphite are subjected to high temperature and pressure, e.g., by a grinding process, sufficient to cause diamond nuclei to be formed.

Abstract: Wire is produced from wire rod by moving the rod lengthwise through first and second cutting tools, the first of which gouges out continuous chips from the rod surface, leaving lands between the grooves so formed, and the second shaves off those lands.