Abstract: This discloses an improved sine bar for accurate measurement of angles for machining operations, and methods of its use. This comprises a rectangular elongated base member, projecting from opposite ends of which are cylindrical connecting rods. A conforming reference bar is hingedly connected to the base member, and has a cylindrical bearing pin fastened beneath one end. When the sine bar is open to accommodate one or more calibrated gauge blocks, a spring-biased chain keeps the gauge block(s) in position between the base member and the bearing pin. A recess in the base member permits measurement of small angles. This device is especially adapted for use in setting up a lathe compound to calibrated angular positions, but is also useful for other types of milling and machining operations in which the sine bar rests on a flat surface.

Abstract: Collet arbor especially adapted for use in computerized numerical controlled turning and milling procedures.The latter comprises four coaxially assembled elements:a clamping holder sleeve having a screw-threaded socket at the inner end, and a smooth, cylindrical interior except for an internal screw-threaded step, near the outer end;an externally-flanged hollow cylindrical adapter comprising an annular recess at its outer end and a stepped shank which screws into the screw-threaded step of the holder;a bushing with a flanged end which fits into the recessed adapter providing an inwardly-tapered mouth and a cylindrical barrel interposed into the adapter and holder for accommodating a collet; anda draw-screw having a hollow, internally-threaded head, externally smooth, which has its schank screwed into the holder socket so that the screw moves slidably in an axial direction in the cylindrical interior of the holder, the draw-screw head disposed to bear against the inner edge of the bushing barrel.