We take it for granted that the metal parts in the machines we use will be well formed, well designed, and functional. But regardless of the end product, all metal parts must journey through several phases before they find their way into the struts of a building or the scalpel of a surgeon. Ore is mined, smelted, blasted, refined, shaped, and cut in the pieces we need. But, as any factory manager can tell you, the process is far from finished even then.
Burrs take up a significant amount of time and money in any manufacturing process. A burr is any curl, shaving, or otherwise unwanted and protruding piece of metal left after the use of cutting tools and even some pouring and molding processes. Every single metal part that is cut, formed, or shaped must be “finished”, and the first step in finishing any piece is the use of deburring tools, which cut away the burrs and leave a smooth outer surface, inner surface, or edge.
Deburring tools can come in a variety of styles and shapes. Technically, abrasive belts and sanders used on wooden pieces are deburring tools, though today the term “deburring” is mainly applied to metalworking. Interestingly enough, many deburring tools are still operated by hand, which allows for precision work and immediate inspection. Common metal deburring tools are made from extremely hard metals, such as carbide or “high speed” steel.
For mass produced parts, however, machines can be programmed to “follow” a drilled hole or a cut edge with a deburring tool. This method adds another layer of complexity to an already complex process, but can save a factory massive amounts of time and manpower (ergo, money) in the overall manufacturing process. This does not completely negate the need for hand tools. Facilities that use mechanical deburring tools as their primary method must still inspect each finished product, and inspectors will often hand deburr any remaining defects as they find them.
Machine parts must work at peak efficiency, and to do that, they must fit together perfectly. The components of a hydraulic pumps, for example, must function smoothly and with no appreciable loss of pressure or energy, in order to properly power their hydraulic cylinders, which may then, in turn be used in the creation of some other machine part. It is indeed an intricate process, but one that has allowed us reach a manufacturing potential undreamed of by our Bronze Age predecessors.