Washer (hardware)

A washer is a thin plate (typically disk-shaped) with a hole (typically in the middle) that is normally used to distribute the load of a threaded fastener, such as a screw or nut. Other uses are as a spacer, spring (belleville washer, wave washer), wear pad, preload indicating device, locking device, and to reduce vibration (rubber washer). Washers usually have an outer diameter (OD) about twice the width of their inner diameter (ID).

Washers are usually metal or plastic. High quality bolted joints require hardened steel washers to prevent the loss of pre-load due to Brinelling after the torque is applied.

Rubber or fiber gaskets used in taps (or faucets, or valves) to stop the flow of water are sometimes referred to colloquially as washers; but, while they may look similar, washers and gaskets are usually designed for different functions and made differently.

Washers are also important for preventing galvanic corrosion, particularly by insulating steel screws from aluminium surfaces.

Free energy

Free energy may refer to:

In science:

In economics:

Washing machine

A washing machine (laundry machine, clothes washer, or washer) is a machine used to wash laundry, such as clothing and sheets. The term is mostly applied to machines that use water as opposed to dry cleaning (which uses alternative cleaning fluids, and is performed by specialist businesses) or ultrasonic cleaners.

Washing by hand

Laundering by hand involves soaking, beating, scrubbing, and rinsing dirty textiles. Before indoor plumbing, the housewife also had to carry all the water used for washing, boiling, and rinsing the laundry; according to an 1886 calculation, women fetched water eight to ten times every day from a pump, well, or spring. Water for the laundry would be hand carried, heated on a fire for washing, then poured into the tub. That made the warm soapy water precious; it would be reused, first to wash the least soiled clothing, then to wash progressively dirtier laundry.

Removal of soap and water from the clothing after washing was originally a separate process. First, soap would be rinsed out with clear water. After rinsing, the soaking wet clothing would be formed into a roll and twisted by hand to extract water. The entire process often occupied an entire day of hard work, plus drying and ironing.

Mechanical engineering

Mechanical engineering is the discipline that applies the principles of engineering, physics, and materials science for the design, analysis, manufacturing, and maintenance of mechanical systems. It is the branch of engineering that involves the design, production, and operation of machinery. It is one of the oldest and broadest of the engineering disciplines.

The engineering field requires an understanding of core concepts including mechanics, kinematics, thermodynamics, materials science, structural analysis, and electricity. Mechanical engineers use these core principles along with tools like computer-aided design, and product lifecycle management to design and analyze manufacturing plants, industrial equipment and machinery, heating and cooling systems, transport systems, aircraft, watercraft, robotics, medical devices, weapons, and others.

Mechanical engineering emerged as a field during the industrial revolution in Europe in the 18th century; however, its development can be traced back several thousand years around the world. Mechanical engineering science emerged in the 19th century as a result of developments in the field of physics. The field has continually evolved to incorporate advancements in technology, and mechanical engineers today are pursuing developments in such fields as composites, mechatronics, and nanotechnology. Mechanical engineering overlaps with aerospace engineering, metallurgical engineering, civil engineering, electrical engineering, manufacturing engineering, chemical engineering, industrial engineering, and other engineering disciplines to varying amounts. Mechanical engineers may also work in the field of biomedical engineering, specifically with biomechanics, transport phenomena, biomechatronics, bionanotechnology, and modeling of biological systems.

Do it yourself

Do it yourself, also known as DIY, is the method of building, modifying, or repairing something without the direct aid of experts or professionals. Academic research describes DIY as behaviors where "individuals engage raw and semi-raw materials and component parts to produce, transform, or reconstruct material possessions, including those drawn from the natural environment (e.g. landscaping)". DIY behavior can be triggered by various motivations previously categorized as marketplace motivations (economic benefits, lack of product availability, lack of product quality, need for customization), and identity enhancement (craftsmanship, empowerment, community seeking, uniqueness)

The term "do-it-yourself" has been associated with consumers since at least 1912 primarily in the domain of home improvement and maintenance activities. The phrase "do it yourself" had come into common usage (in standard English) by the 1950s, in reference to the emergence of a trend of people undertaking home improvement and various other small craft and construction projects as both a creative-recreational and cost-saving activity.