Body in white

Body in white (BIW) refers to the stage in the automobile manufacturing in which a car body's components have been joined together, using one or a combination of different techniques: welding (spot, MIG/MAG), riveting, clinching, bonding, laser brazing etc.BIW is termed before painting and before the engine, chassis sub-assemblies, or trim (glass, door locks/handles, seats, upholstery, electronics, etc.) have been assembled in the frame structure. Body in white (BIW) refers to the stage in the automobile manufacturing in which a car body's components have been joined together, using one or a combination of different techniques: welding (spot, MIG/MAG), riveting, clinching, bonding, laser brazing etc.BIW is termed before painting and before the engine, chassis sub-assemblies, or trim (glass, door locks/handles, seats, upholstery, electronics, etc.) have been assembled in the frame structure. The name derives from manufacturing practices before steel unibody monocoques — when automobile bodies were made by outside firms on a separate chassis with an engine, suspension, and fenders attached. The manufacturers built or purchased wooden bodies (with thin, non-structural metal sheets on the outside) to bolt onto the frame. The bodies were painted white prior to the final color. A folk etymology for body in white suggests the term derives from the appearance of a car body after it is dipped into a white bath of primer (undercoat paint)— despite the primer's actual gray color. This could also refer to when car bodywork would be made of timber - all timber products, furniture etc., are considered to be 'in the white' when at the stage of raw timber before finishing/varnishing. In car design, the body in white phase refers to the phase in which the final contours of the car body are worked out, in preparation for ordering of the expensive production stamping die. Extensive computer simulations of crash-worthiness, manufacturability, and automotive aerodynamics are required before a clay model from the design studio can be converted into a body in white ready for production. Factories may offer BIW cars to racers, who then may replace up to 90% of the car with aftermarket parts, and niche manufactures like Ruf Automobile start their cars with BIWs from other makers. A related term in the automotive industry is 'body in red'. This can refer to a car body that is formed of alternate materials such as composites rather than conventional metal; these composite materials, such as carbon fiber, are black rather than white. Body-in-black can also refer to a step in the design process in which a mock-up of a new car skin is built, in order to perform exacting measurements during the design and pre-production processes.