A parts washer is a piece of equipment used to remove contaminants or debris, such as dirt, grime, carbon, oil, grease, metal chips, cutting fluids, mold release agents, ink, paint, and corrosion from workpieces. Parts washers are used in new manufacturing and remanufacturing processes; they are designed to clean, degrease and dry bulk loads of small or large parts in preparation for assembly, inspection, surface treatment, packaging and distribution. Parts washers may be as simple as the manual "sink-on-a-drum" common to many auto repair shops, or they may be very complex, multi-stage units with pass-through parts handling systems. Parts washers are essential in maintenance, repair and remanufacturing operations as well, from cleaning fasteners, nuts, bolts and screws to diesel engine blocks and related parts, rail bearings, wind turbine gears boxes and automotive assemblies. A parts washer is distinctly different from a pressure washer in that parts washers typically clean parts automatically in an enclosed cabinet, while pressure washers typically have a single spray jet mounted at the end of a manually operated wand. Modern industrial technology makes it possible to combine many parts of the finishing process into one. As an integrated part of the manufacturing process, automatic parts washers are able to load, wash, rinse, dry and unload parts in an automatic cycle. In industry, chemical solvents were typically used to remove oils, grease and dirt during the cleaning process, but recent environmental concerns and regulations have encouraged the innovation of water based detergents for parts cleaning. Today, most parts washers use a variety of alkaline based detergents as the cleaning chemical. History Parts washers were originally developed for use in automotive transmission and engine repair shops as a way to improve the function of simple soak tanks. Soak tanks are vats filled with a mixture of water and detergent, which take hours to "soften" the built-up road grime, fluids, tars and oils enough to be manually rinsed off prior to disassembly and repair. Since the late 60's many methods of parts cleaning have been developed with improved levels of safety and lessened environmental impact. Stoddard solvent, gasoline, diesel fuel, and kerosene were commonly used to clean and degrease parts. Then, chlorinated solvents in vapor degreasers became an industry standard. During the 1980s environmental and safety issues led to the banning of chlorinated solvents for parts cleaning. Aqueous-based cleaning systems took on new prominence that led to many improvements,