walking cam

See aerial cam.

warp

As opposed to hem curved outboard and hem deflection warp is the term used for the local curve at the hem edge. (See Figure W1 and Figure W2)

wear plates

“Plates made of hardened tool, steel, or bronze.  Used where dies receive the greatest wear to enable resurfacing and shimming of the plates to renew wear surfaces.  Normally they are used in pairs, one steel and the mating one bronze” (Automotive Steel Partnership, 1991, p. 18).

web

(1) A narrow strip which connects the part to the skeleton or adjoining part. (2) The center, along the axis, of a twist drill.  (3) Any narrow section of a die connecting one section to another.

window

A separately mounted steel used to gain access to perishable details or other die components.  Also called pad window, stripper insert, or insert.

wiping steel

See flange steel.

work (strain) hardening coefficient

Shown as n. It is a mathematical value in the generalized (Swift’s or Krupkowski’s) power law. (See Figure W3)

work hardening

See strain hardening.

workability

See formability.

worldscan

“An instrument that employs ultrasonic sound waves to measure the thickness of steel” (Automotive Steel Partnership, 1991, p. 17). In order for the WorldScan “System” to operate as desired, it must be calibrated to accommodate the external factors which influence the fluorescing phenomenon.  All film coatings fluoresce uniquely.  Also, the substrates (bases) to which the films are applied affect the ways the film coatings adhere macroscopically to the surfaces of those substrates.  Calibrations must film coatings adhere macroscopically to the surfaces of those substrates.  Calibrations must be set up for each base and film combination. Produced by CMT, Inc. in Cleveland, OH, is a weight coating analyzer which operates by the ultraviolet fluorescence principal.  The WorldScan contains an internal 370 NM ultraviolet lamp source which excites a film coating at this wavelength.  The film coating responds to this excitation by emitting energy (called fluorescing).  The amount of fluorescing is proportional to the amount of film present; thus the greater the amount of film present, the greater the fluorescence.  The WorldScan uses this fluorescing signal to give the end result of a calibrated reading in final engineering units of (mg of coating) / (ft² of sheet metal). The WorldScan is calibrated by collecting data comprised of the amount of fluorescence of a base and film combination for a given amount of coating per square foot of substrate.  Coating weights are typically measured by a laboratory scale.  The calibration data are then fit to an equation, which can be programmed into the WorldScan unit.  The Control Software for the WorldScan provides the capability to program a linear equation of the form:  y = Ax + B which is most common in the typical range of applications.  (CMT, Inc., Cleveland, OH)

wrap forming

See stretch forming.

wring fit

Class of fit which is between a slip fit and a press fit.  Usually requiring a slight twisting action to put the parts together.

wrinkling

The maximum tensile stress that a material can withstand prior to failure. Figure 1 labels tensile strength on a stress/strain curve of a tensile test. “A wavy condition on metal parts due to buckling under compressive stresses” (Automotive Steel Partnership, 1991, p. 18).