Publisher's Synopsis
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1907 edition. Excerpt: ... well to send templets of the desired shapes, and to state how nearly exact the cutters must be. If any part of the outline is to be a straight line the sketch should clearly show this, and if any part is to be circular the radius should be given. Unless instructions have been given to the contrary, mills are generally made and hardened to cut steel or iron. sharpening A dull mill wears away rapidly and does poor work. Accordingly care must be taken to keep mills sharp. In sharpening them it is necessary to be very careful that the temper should not be drawn. Grade of The emery wheel should be of the proper grade as to wheel hardness and as to the size of the emery. The wheel 'th'e'work?1' should be soft enough so that it can be easily scratched with a pocket knife blade, and the emery should not be finer than 90 nor coarser than 60. As a rule, the coarser and softer the wheel, the faster it should run, although the periphery speed should not exceed 5000 feet per minute. width of A wheel of the proper grade should be used with the Wheel, face not to exceed " wide. If the wheel glazes, the temper of the cutter will be drawn. In such a case, if the wheel is not altogether too hard, it can sometimes be remedied by reducing the face of the wheel to about yi" or by reducing the speed, or by both. Before using, a wheel should be turned off so that it will run true. A wheel that glazes immediately after it has been turned off can sometimes be corrected by loosening the nut and allowing the wheel to assume a slightly different position when it is again tightened. Another method of preventing a wheel's glazing is to use a piece of emery wheel, a few grades harder than the wheel in use, on the face of the wheel, whereby the cutting...
