Machine Assembly and Manufacturing Processes
Assembling (joining of the pieces) is done by welding, binding with adhesives, riveting, using threaded fasteners, or even further bending in the form of a crimped seam. Structural steel and sheet metal are the usual starting materials for fabrication, along with the welding wire, flux, and fasteners that join the cut pieces. As with other manufacturing processes, both human labor and automation are commonly used. Adequate installation of machinery is fundamental to maximizing reliability and minimizing the costs of the life cycle. On the contrary, an incorrect installation is a permanent source of idle time, problems with product quality, decreased capability, and high operating costs.
An assembly line is a manufacturing process in which interchangeable parts are added to a product in a sequentially to create an end product. In most cases, a manufacturing assembly line is a semi-automated system through which a product moves. At each station along the line, some part of the production process takes place. The workers and machinery used to produce the item are stationary along the line, and the product moves through the cycle, from start to finish.
Key Machining Terms and Definitions
- Apron: The portion of a lathe carriage that contains the clutches, gears, and levers for moving the carriage. It also protects the mechanism.
- Back rake: The angular surface ground back from the cutting edge of cutting tools.
- Caliper, gear tooth: A special caliper used to measure both the thickness and the depth of a gear tooth.
- Carbonizing: The process of adding carbon to the outer surface of steel to improve its quality by heat-treating it in contact with a carbonaceous material.
- Deburr: To remove sharp edges.
- Die: A tool used to form or stamp out metal parts; also, a tool used to cut external threads.
- Dressing: The act of removing the glaze and dulled abrasives from the face of a grinding wheel to make it clean and sharp.
- Emery: A natural abrasive used for grinding or polishing. It is being largely replaced by artificial abrasives.
- Face: To machine a flat surface, as in the end of a shaft in the lathe. The operation is known as facing. Face milling.
- Gage: Any one of a large variety of devices for measuring or checking the dimensions of objects.
- Gear blank: A stamping, casting, or any piece of material from which a gear is to be machined. It is usually a disk.
- Hex: A term used for anything shaped like a hexagon.
- Jig: A production work-holding device that locates the workpiece and guides the cutting tool.
- Kerf: The width of cut made by a saw.
- Land: The surface on the periphery of a rotary cutting tool, such as a milling cutter, drill tap, or reamer, which joins the face of the flute or tooth to make up the basic cutting edge.
- Lead: The distance a thread will advance along its axis in one complete revolution.
- Malleable: Capable of being extended or shaped by hammering or rolling.
- Mandrel: A precision-made tapered shaft to support work for machining between centers.
- Necking: Machining a groove or undercut in a shaft to permit mating parts to be screwed tightly against a shoulder or to provide clearance for the edge of a grinding wheel.
- Oilstones: Molded abrasives in various shapes used to hand-sharpen cutting tools.
- Pawl: A pivoted lever or sliding bolt that secures, as an automatic directional table control on a grinder.
- Rake: The surface of a cutting tool against which the chips bear while being severed.
- Sandblasting: A process of blowing sand by compressed air with considerable force through a hose against an object.
- Taper: A uniform increase or decrease in the size or diameter of a workpiece.
- Universal vise: A vise designed for holding work at a double or compound angle.
- Wheel dresser: A tool or device for dressing or truing a grinding wheel.