Because millwrights often decide what device to use for moving machinery, they must know the load-bearing properties of ropes, cables, hoists, and cranes. New machinery sometimes requires a new foundation. Millwrights either personally prepare the foundation or supervise its construction, so they must know how to read blueprints and work with building materials such as concrete, wood, and steel. When assembling machinery, millwrights fit bearings, align gears and wheels, attach motors, and connect belts according to the manufacturer's blueprints and drawings. When a high level of precision is required, devices such as lasers may be used.
Millwrights also use hand and power tools, cutting torches, welding machines, and soldering guns.
Some millwrights use metalworking equipment such as lathes or grinders to modify parts to specifications. The increasing level of automation found in most industries means that there are more sophisticated machines for millwrights to install and maintain. This machinery often requires special care and knowledge, so millwrights often work closely with computer or electronic experts, electricians, and manufacturer's representatives to install it. In addition to installing and dismantling machinery, many millwrights repair and maintain equipment. This includes preventive maintenance, such as lubrication, and fixing or replacing worn parts.