Shop management and systems; a treatise on the organization of machine building plants and the systematic methods that are essential to efficient administration

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1918 Excerpt: ...on turning and planing machines is considered an important function of the tool store-room in many plants where this system has been put into use. There are a number of reasons why machine operators are not permitted to grind those tools that are adapted to be ground by hand. In the first place, numerous experiments have proved that slight changes in the shape of a tool of the type used for turning, planing, etc., may have a decided effect on its cutting qualities and upon the length of time that the tool can be used before regrinding is necessary; therefore, it naturally follows that these tools should all be given whatever shape has proved to be most effective. In other words, tools should be standardized, especially as regards the shape of the cutting ends. The development of special tool-grinding machines and the establishment of tool-grinding departments in many shops has made it possible to have all the cutting tools uniform and ground according to approved principles. Disadvantages of Grinding Tools by Hand.--When each man is independent as to the grinding of tools, the results depend upon his experience, skill, or interest in doing things the right way. Some workmen grind their cutting tools properly and others violate every principle of tool grinding. Correct grinding is not always done even when the workman knows how different tools should be formed. Sometimes the shape of the tool is sacrificed in order to grind it quickly or easily. The way an old shopmate used to grind thread tools illustrates this point. The plan followed was to bevel the top of the face downward toward the front, because the narrow point of the tool could easily be ground away. The scheme worked well and the edge was sharp, but the " negative rake " neither improved...