Fitting and Assembly Tools

tools used in the modular and straight-line assembly of machines to join components and in adjustment operations.

Fitting and assembly tools used in assembling machine components may be either manual or power-driven. Manual tools include standard or special tools for assembling threaded connections, including wrenches and screwdrivers, standard and soft hammers and mandrels for pressing in parts, dies and dollies for riveting work, rollers, and various tools for installing elastic split rings and washers. Power-driven tools include hand-held pneumatic and electric machines for fastening threaded connections, such as screwdrivers and nut and bolt drivers, pneumatic and electric hammers, portable clamps for pressing and riveting, power-driven rollers, and special devices for installing elastic parts, such as piston rings, split locking rings, and springs.

The use of power-driven tools increases the labor efficiency of assemblers by a factor of 10 to 20 as compared with the labor efficiency obtained with manual tools. Power-driven tools are widely used in mass and large-lot production operations. An important prerequisite for the use of power-driven tools is the training of assemblers in specialized lines of work and the standardization of fastening components.

Standard manual tools are used in adjustment operations in single-unit or small-lot production, including filing, deburring, scraping, lapping, cutting of lubrication grooves, and drilling and reaming of predrilled holes. Such tools include files, scrapers, lapping tools, various types of chisels, drills, and reamers. Some specialized tools are also used, such as lapping tools, mandrels, and templates.

The amount of labor required for adjustment work can be reduced by the use of power-driven equipment, such as manual, pneumatic, or electric drilling machines, filing and scraping machines, pneumatic hammers, and mechanical lapping equipment. It may also be reduced by substituting machine operations for manual operations, for instance, by grinding instead of filing or by fine boring holes instead of scraping. If the principle of interchangeability is applied to assembly, adjustment operations can be eliminated.