Chapter S: S System, Stable

S

S

Symbol for the sulfur.

sacrificial protection

The planned corrosion of a metal coating for the sake of protecting the substrate metal. For example, when zinc is in contact with a less reactive metal, such as steel, a galvanic cell is created. When an electrolyte such as atmospherically contaminated moisture is present, an electric current will flow in the cell and the zinc coating is sacrificed to protect the steel.

See also galvanizing.

SAE

Abbreviation for Society of Automotive Engineers. The initials of this organization are used in its tests and specifications for motor oils, fuels, and steels.

SAE steel

See also AISI/SAE steel designations.

safe edge

An edge of a file that is made smooth or uncut, so that it will not injure that portion or surface of the workplace with which it may come in contact during filing.

sal ammoniac

See also ammonium chloride.

salt bath

A molten mixture of chemicals that may be as high as 2,399 F/1,315 C, used to harden and temper metals and for annealing both ferrous and nonferrous metals, used to enhance fatigue strength, wear, and corrosion resistance.

salt bath tempering

A heat-treatment process involving the use of molten salt baths for drawing or tempering operations that result in the relief of internal strain in hardened steel, and thus increases toughness. Tempering temperatures range from 300 F/145 C to 1,150 F/621 C. The temperature should be increased gradually, for example, from 300 F/149 C to 400 F/204 C up to the tempering temperature, which may range from 380 F/193 C...