Engineering Definitions

The area of a part that cannot be formed when in die position with direct vertical travel of the press ram.

Source: The OHIO State University

A tear drop shaped area machined in the shank of a punch by a ball nose cutter. This allows the punch to be accurately located and locked in a retainer by a ball.

Source: The OHIO State University

Rough grinding, by hand, of excess stock in a die.

Source: The OHIO State University

(1) Stationary platen of a press to which the lower die assembly is attached. (2) Stationary part of the shear frame that supports the material being sheared and the fixed blade.

Source: The OHIO State University

A flange reinforced by a low ridge, used mostly around a hole.

Source: The OHIO State University

The angular condition on the working surface of a trim or form steel caused by excessive wear.

Source: The OHIO State University

The angle through which a bending operation is performed, that is, the supplementary angle to that formed by the two bend tangent lines or planes.

Source: The OHIO State University

The inside radius of a bent section.

Source: The OHIO State University

It is defined as the minimum bending radius (shown as Ri, inner radius) attainable by a given material

Source: The OHIO State University

The straining of material, usually flat sheet or strip metal, by moving it around a straight axis lying in the neutral plane. Metal flow takes place within the plastic range of the metal, so that the bent part retains a permanent set after removal of the applied stress. The cross section of the bend inward from the neutral plane is in compression; the rest of the bend is in tension. See also bending stress.

Source: The OHIO State University

The straining of material, usually flat sheet or strip metal, by moving it around a straight axis lying in the neutral plane. Metal flow takes place within the plastic range of the metal, so that the bent part retains a permanent set after removal of the applied stress. The cross section of the bend inward from the neutral plane is in compression; the rest of the bend is in tension. See also bending stress.

Source: The OHIO State University

Dies used in presses for bending sheet metal or wire parts into various shapes. The work is done by the punch pushing the stock into cavities or depressions of similar shape in the die or by auxiliary attachments operated by the descending punch.

Source: The OHIO State University

Various types of machinery equipped with two or more rolls to form curved sheet and sections.

Source: The OHIO State University

A stress involving tensile and compressive forces, which are not uniformly distributed. Its maximum value depends on the amount of flexure that a given application can accommodate. Resistance to bending can be termed stiffness.

Source: The OHIO State University

“The upper and lower holding surfaces which control metal flow around a shape to be formed in a draw operation” (Automotive Steel Partnership, 1991, p.2). Also see blank holder and draw ring.

Source: The OHIO State University

A long narrow trim steel quite often mounted from the side.

Source: The OHIO State University

(1) In forming, a piece of sheet material, produced in cutting dies, that is usually subjected to further press operations. (2) A piece of stock from which a forging is made; often called a slug or multiple. (3) “A pre-cut metal shape for a subsequent press operation” (Automotive Steel Partnership, 1991, p.2).

Source: The OHIO State University

(1) The technique of determining the size and shape of a blank. (2) The resultant flat pattern.

Source: The OHIO State University

The part of a draw die which holds the work piece against the draw ring to control metal flow. A blank holder is also called binder, binder ring, or ring. That part of a forming die which holds the blank by pressure against a mating surface of the die to control metal flow and prevent wrinkling. The blank holder is sometimes referred to as “hold down” or binder area. Pressure applied by mechanical means, springs, air, or fluid cushions (Automotive Steel Partnership, 1991, p.2).

Source: The OHIO State University

Blank holder force is applied to the perimeter of a sheet during a deep drawing operation to suppress wrinkling and control metal flow. Also referred to as the binder, pressure pad or draw ring.

Source: The OHIO State University

Blank holder pressure is the pressure pattern on the blank that results from applying a blank holder force. “The pressure exerted by the blank holder against the blank. This pressure is normally adjustable to control metal flow during the drawing.” (Automotive Steel Partnership, 1991, p.2).

Source: The OHIO State University

The operation of punching, cutting, or shearing a piece out of stock to a predetermined shape.

Source: The OHIO State University

“A variable that potentially can affect a response variable in an experiment but is not of interest as a factor grouped by experimental units treated in a similar way in an experimental design” (Moen, R. D., Nolan, T. W., Provost, L. P., 1991, p.402).

Source: The OHIO State University

A plate to which dies can be fastened- the assembly is secured to the top surface of a press bed. In press forging, such a plate may also be attached to the ram.

Source: The OHIO State University

A raised portion of a casting, die, or part such as bosses for tie slots on die shoes.

Source: The OHIO State University

Press-brake bending process in which the upper die (punch) enters the lower die and coins or sets the material to eliminate springback.

Source: The OHIO State University

Adjustable blocks mounted under a pad to determine the proper height of the pad when the die is closed.

Source: The OHIO State University

“A stamp or weld mark used in a form die to signify that the die is on the bottom. Usually positioned in a scrap area of the part” (Automotive Steel Partnership, 1991, p.2).

Source: The OHIO State University

A precision made box containing cam slide and driver.

Source: The OHIO State University

A pre-draw die to gain material in the areas of a deep draw to help prevent the fracture of the metal in these areas.

Source: The OHIO State University

(1) An uncontrolled deformation pattern perpendicular to the surface of a sheet caused by compressive stresses. Buckling in the flange of the part is referred to as wrinkling, and buckling in the wall of the part is referred to as puckering.  (2) A bulge, bend, kink, or other wavy condition of the workpiece caused by compressive stresses.

Source: The OHIO State University

The process of increasing the diameter of a cylindrical shell (usually to a spherical shape) or of expanding the outer walls of any shell or box shape whose walls were previously straight.

Source: The OHIO State University

A thin ridge or roughness left on forgings or sheet metal blanks by cutting operations such as slitting, shearing, trimming, blanking, or sawing.

Source: The OHIO State University

A common term for debarring or smoothing the rough cut edges of metal.

Source: The OHIO State University

A pair of shaped dies used to combine preliminary forging operations, such as edging and blocking, or to loosen scale.

Source: The OHIO State University

A small cylindrical die steel with an opening larger than the punch point size, generally by a percentage of the thickness of the material being pierced. Also called die button or pierce button.

Source: The OHIO State University

A generic term referring to the amount that one steel passes over or thru another steel.

Source: The OHIO State University