A special steel alloy which is largely used for turning tools in engine lathes and which will cut ordinary steel when the latter is revolved at a high surface velocity is called high speed steel. A tool made of high speed steel will not lose its temper and will keep its cutting edge hour after hour if they are kept cool by a stream of water running on them. A good high speed steel for machine tools is known by the trade name of blue-chip and is manufactured by the Firth-Sterling Steel Company of Pittsburg, Pa.
APPENDIX O
SOME ELECTRICAL SYMBOLS, TERMS AND FORMULAS
| Symbols | Terms | |
|---|---|---|
| E or EMF | = | Electromotive Force |
| I | = | Intensity of Current |
| R | = | Resistance |
| C | = | Capacity |
| Q | = | Quantity of Current |
| = | Magneto-Motive Force | |
| = | Reluctance (magnetic resistance) | |
| µ | = | Magnetic Permeability |
| W | = | Electric Energy |
| P | = | Electric Power |
SOME DEFINITIONS
E or EMF, or electromotive force, is the force that moves a current through a conductor.
I, or intensity of current, or current as it is called for short, is the flow of electricity through a conductor.
R, or resistance is that property of a conductor which opposes the flow of the current.