Secondary to seller

Secondary type glider to Selectivity

Secondary-type glider. (Aero.) A glider designed to have better aero­dynamic performance than the primary type, but rugged enough for the use of pilots with limited training.
Secound-elass lever. (Mech.) A lever with the weight applied between fulcrum and power.
Second cut. (Meta/wk.) Indicates spacing of teeth on a file. Second cut indicates a degree or rough­ness between bastard and smooth, and may be either single or double cut.
Seconds. Any artilces not of first qual­ity. In the printing trade "seconds" is usually applied to paper.
Section. (Bldg. and Mech. Drg.) A drawing representing the internal parts of an object as if it had been straight through vertically or hori­zontally. Also partial sections may be taken through particular parts.
Sectional. (1) Of, or pertaining to, a section or district; local; consist­ing of sections; divisible into sec­tions. (2) A drawing which shows some portion cut away, in order that the drawing may be more eas­ily understood, is called a "sec­tional view."
Sector. (Geom.) (I) A part of a circle bounded by two radii and the arc subtended by them. (2) Any me­chanical part of similar shape. .
Sedan. (Auto.) An enclosed fourdoor permanent-type body with fullwidth cross seats front and rear.
Sediment. The matter which settles at the bottom of a liquid.
Sedimentary rock. (Min.) Rock formed under water by pressure or by cementation. .
Segment. The part of a circle included between the chord and its arc.
Segmental arch. (Masonry) An arch whose curve is an arc of a circle, but less than a semicircle.
Segmental rack or segmental wheel. (Mach.) An arc or portion of a gear wheel, used for imparting rever­sible motion to a spindle.
Segregation. The separating of parts as from a main body and bringing these parts together as a unit.
Sesmograph. (slzmO-grit) (Phys.)An instrument which automatically records an earthquake shock.
Sesize. The sticking together or ad­hering of surfaces, which normally move freely against each other, due to heat generated by friction caused by lack oflubrication. Such parts ~e often said to be "frozen" See Galling.
Selectivity. (Radio) The ability of a set to clearly receive one radio sta­tion signal while eliminating all others.

self acting to seller screw thread
Self acting. Operating automatically; performing an operation wit~out outside assistance.
Selfaligning bearing. A bearing sup­ported in such a manner that it can readily adjust itself to the align­ment of its shaft.
Self-centering. (M ech.) The automatic setting, locating, or marking of a cylindrical piece of work.
Self-centering chuck. (Mach.) A chuck which automatically centers a piece of work through the simul­timeous movement of the jaws.
Self-center-ing or bell center punch. (Mach.) A center punch which slides in a bell-mouthed casing. A
fairly accurate centering is secured by placing the bell mouth over the end of the piece to be marked, then tapping the punch with a ham­mer.
Self-energizing. (Auto.) The tendency of a brake mechanism to increase the brake pressure, due to the ro­tation of the brake drums.
. Self-excitation. (Elec.) Direct current gotten from the brushes of a d.c. generator to provide current for its electromagnetic field. In alterna­tors the term returns to a d.c. gen­erator built on the alternator. shaft. Used to provide direct current for the alternator field.
Self-excited. (Elec.) A machine which generates its own current for sup­plying its field.
Sief-excited alternator. alternating-current(Elec.) An generator which also produces through one of several ways a direct current for magnetizing its main fields.
Self-hardening steel. (Metal.) An alloy tool steel which hardens when cooled in air.
Self-induced current. (Elec.) The current produced by the self­induced e.m.f., set up in a coil when the magnetic field of the same coil changes in direction or intensity.
Self-inductance. (Elec.) The phenom­en2 of electromagnetic induction which takes place between the turns of a coil in a circuit.
Self-induction. (ELec.) The reaction of the magnetic field of a coil upon itself.
Self-locking setscrews. (Mach.) There are several patented types of setscrews which resist the loos­ening effect due to vibration. One type has left-hand spiral knurling at the point, another has a deeply slotted head, the slot being spread to offer resistance.
Self-opening die. (Mach.) A die which . opens automatically to permit its removal after the thread-cutting operation is finished. Self-tapping screw. A type of screw designed to cut its own threads in metal. Such screws are used most satisfactorily on the softer metals of not too heavy gauge.
Sellers screw thread. (Mach.) The U.S. Std. or National coarse thread of V type, with fits at top and bot­
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