Waste yarn lubrication: lubrication system that delivers the lubricant to the bearing and journal surface by the capillary action of an oil-soaked fibrous material like yarn or textile waste, in contact with a relatively slow moving journal. Like pad lubrication, this form of lubrication has been used in over-theroad railway cars.

Waste, oily: term applied to all fuels, lubricants and petroleum products that may cause environmental pollution because of leakage and spills or as part of plant waste.

Water glycol: FT hydraulic fluid composed of water and one of the glycols.

Water resistance (grease): the ability of a lubricating grease to withstand the addition of water to the lubricant system without adverse effects, generally rated by the following criteria: washout resistance (ASTM D-1264); water absorption; water corrosion resistance (ASTM D-1743) and water sprayoff resistance (ASTM D-4049).

Wax: the aliphatic paraffin series of hydrocarbons with high boiling points and high molecular weight; classes include paraffin (crystalline), microcrystalline and petrolatum (amorphous and microcrystalline). Petrolatum is obtained from the heavy residual stock; heavier grades are used for rust prevention and wire rope lubrication (see petrolatum).

Wax appearance point – the temperature at which wax begins to precipitate out of a distillate fuel.
Wear of metals – the loss of surface material due to motion between two surfaces in contact.
Wetting agent (lubricants): an oiliness additive; an additive that adsorbs to metal to enhance the spreading of a lubricant.

Wetting agent (cleansers): a surfactant that, added to water, causes the water to spread more easily over the surface of another material. Wetting agents do not usually impart any detergent or emulsifying properties to water.

White oils: light-colored, usually highly-refined mineral oils frequently employed in pharmaceutical and medicinal preparation and used as bases for creams, salves and ointments. White oil lubricants are used where color and/or environmental concerns are important.

White petroleum jelly: the whitest grade of petrolatum.

Wick lubrication: lubrication system that uses a wick to deliver the lubricant to the bearing surface.

Wiping: the smearing or removal of material from one point, often followed by the redeposition of the material at another point, on the surfaces of two bodies in sliding contact; a form of wear.

Worked penetration: (ASTM D-217) penetration of a sample of lubricating grease immediately after it has been brought to 77°F and subjected to 60 strokes in a standard grease worker.

Worm gear: a screw-thread-like gear consisting of worm and worm wheel; the worm, made of steel, is the driving gear, and the worm wheel, made of nonferrous metal, is the driven gear. Worm drives have relatively low gear ratios.