Cutting along a line in the workpiece without producing a detached slug from the workpiece.
Source: The OHIO State University
L
Land
(1) Sharpening land the reduced area of a die block or punch that is reground when sharpening is needed. (2) Cutting land – see die life.
Source: The OHIO State University
Laser Beam Cutting
A cutting process that severs material with the heat obtained by directing a laser beam against a metal surface. The process can be used with or without an externally supplied shielding gas.
Source: The OHIO State University
Lead Hit
(1) (Lead Shear) A method of determining the location of the cutting edge on a steel by building approximately one-fourth inch of lead on top of the cutting edge and shearing lead with mating steel. (2) A method of checking how much space is between mating form or flange steels.
Source: The OHIO State University
Leveler Lines
Lines on sheet or strip running transverse to the direction of roller leveling. These lines may be seen upon stoning or light sanding after leveling (but before drawing) and can usually be removed by moderate stretching.
Source: The OHIO State University
Leveling
The flattening of rolled sheet, strip, or plate by reducing or eliminating distortions. See stretcher leveling and roller leveling. The process whereby a coil of steel is flattened through several sets of opposing rollers which first overbend the blank and then progressively bend to true flatness.
Source: The OHIO State University
Leveling Blocks
Blocks used to control the shut height and levelness of a die in a spotting press. Also called stand-off blocks.
Source: The OHIO State University
Lifter
A mechanism for raising a part in a die to a height for advancing it to another station, as in a progressive die, or for ejecting it from the die. Also incorrectly called a kicker or ejector.
Source: The OHIO State University
Liftout
The mechanism also known as knockout.
Source: The OHIO State University
Limit Dome Height
The greatest depth that a material can withstand under the pure stretching of a hemispherical punch. This is a standard measurement of stretch-ability.
Source: The OHIO State University
Limit Switch
A type of electric switch used to control the operations of a machine automatically.
Source: The OHIO State University
Limiting Draw Ratio
The greatest ratio of blank diameter to punch diameter that can be successfully cup-drawn to a particular depth. This is a standard measurement of draw-ability. See also deformation limit.
Source: The OHIO State University
Locator
(1) See jig borer. (2) Lower section of a die on which the part nests. Also called an adapter, boss, die post, horn, master, master plug, and stool.
Source: The OHIO State University
Lock Bead
A ridge constructed around a die cavity to completely restrict metal flow into the die” (American Iron and Steel Institute and Committee of Sheet Steel Producers, 1984, p. 137).
Source: The OHIO State University
Locking Bead
A bead or projection designed to prevent metal flow in a forming operation. Also called lock spleen.
Source: The OHIO State University
Low Profile Screw
A special socket head cap screw which has a head height approximately one-half that of a nominal socket head cap screw.
Source: The OHIO State University
Low Spot
Generally, a local inboard condition on a panel which is usually in a high stress area. Also called birdbath or shadow.
Source: The OHIO State University
Lubricant
Any substance interposed between two surfaces in relative motion for the purpose of reducing the friction and/or wear between them” (Automotive Steel Partnership, 1991, p. 10).
Source: The OHIO State University
Luders Lines
Elongated surface markings or depressions, often visible with the unaided eye, that form along the length of a round or sheet metal tension specimen at an angle of approximately 55' to the loading axis. Caused by localized plastic deformation, they result from discontinuous (inhomogeneous) yielding. Also known as Luders bands, Hartmann lines, Piobert lines, or stretcher strains.
Source: The OHIO State University