B 1
b ft 020 .to 002 . -i- t 0 0 ' ',' Wet I'lirnre .i mc-usit, 'I ri, - .ijni' t i' door rj_ i n Details of solid-carbide drills used successfully on HI t steel harder than 50 HRC. a and b Twist drills, 9 for holes less than 6.4 mm ' lt in. in diameter, c Straight-flute drills, for holes 6.4 mm Va in. in diameter or larger Dimensions given in inches was mosi suitable for drilling H11 steel sheet 57c Cr. 1.59 Mol heat treated to 54 HRC. Two sheets of this material, each 2. It mm 0.083 in. thick,...
Grooves Slots and Keyways
Vertical machines are usually used in preference to horizontal shapers for cutting external or internal grooves. This is particularly true when two or more grooves must be kept in a specific relationship to each other, because indexing for cutting in a vertical plane is usually simpler. External grooves can be machined on shapers to about the same degree of dimensional accuracy as in milling. Holding close dimensions on external grooves cut on a shaper depends largely on the accuracy of Ihe...
Types of Broaches
There are three general categories of broaches solid, shell, and insert-type. Within these categories, broaches can be further classified by the type of cut internal or external hey are designed o make and by the method by which they are actuated push or pull . Of the various types of broaches, the solid pull broach Fig. 13 is probably the most commonly used. Solid broaches are one-piece broaches produced from bar stock Fig. I and 13 . They can be provided with greater dimensional accuracy and...
Fundamental Mechanism off Metal Deformation
Cutting Models. Before the mechanics of machining are presented, a brief discussion of the fundamental nature of the deformation processes is helpful in understanding the assumptions that accompany the mechanics. The machining geometry can be simplified from the three-dimensional oblique geometry, which typifies most industrial processes, to a two-dimensional orthogonal geometry. Figure I compares the oblique and the orthogonal cutting geometries. Orthogonal machining can be obtained in...
Tool Geometry Angle
where p is the density of the work material and t is the feed or uncut chip thickness. Chip thickness is usually greater than the depth of cut, . and is constrained by the rake face of the cutting tool. Shear Angle. There are numerous other ways to measure or compute the shear angle, both during dynamically the cutting process and after statically it has been halted. The shear angle can be measured statically by instantaneously interrupting the cut through the use of quick-stop devices. These...