What is "shearing stress"

Shear \Shear\, n. [AS. sceara. See Shear, v. t.]

1. A pair of shears; -- now always used in the plural, but formerly also in the singular. See Shears.

   On his head came razor none, nor shear.
   --Chaucer.

   Short of the wool, and naked from the shear.
   --Dryden.

2. A shearing; -- used in designating the age of sheep.

   After the second shearing, he is a two-shear ram; . . . at the expiration of another year, he is a three-shear ram; the name always taking its date from the time of shearing.
   --Youatt.

3. (Engin.) An action, resulting from applied forces, which tends to cause two contiguous parts of a body to slide relatively to each other in a direction parallel to their plane of contact; -- also called shearing stress, and tangential stress.

4. (Mech.) A strain, or change of shape, of an elastic body, consisting of an extension in one direction, an equal compression in a perpendicular direction, with an unchanged magnitude in the third direction.

   Shear blade, one of the blades of shears or a shearing machine.

   Shear hulk. See under Hulk.

   Shear steel, a steel suitable for shears, scythes, and other cutting instruments, prepared from fagots of blistered steel by repeated heating, rolling, and tilting, to increase its malleability and fineness of texture.