An electrical plug with two flat prongs and one round one (used as a ground). Typically used with high current devices such as refrigerators.
Three-spindle feed handle
The three-spindle feed handle provides a steady feed with more control over the drill press.
Three-way switch
Switch device, which uses two switches to allow an outlet or light to be activated from either switch.
Three-way valve
A valve with a single inlet and two outlets. The valve can be set so that either outlet is open.
Three-wire system
An electrical system using two hot leads and one ground. Typically used for 240-volt service.
Threshold (iaq)
The contaminant dose or exposure level below which there is no expected significant effect.
Threshold limit value
Levels of airborne concentrations of chemicals, used to determine safety limits.
Thrift institution
Depository institution, such as mutual savings banks. If organized as mutual associations, depositors are shareholders. They provide mortgages.
Throat
The cutout of a shingle, or the narrowing passage located between a fireplace and smoke chamber or flue.
Throatplate
The underside portion of some faucet spouts which also use a top shroud to cover an assembled faucet waterway. The throatplate is only visible when viewed from a very low angle.
