Engineering Definitions

A press having uprights or-housing resembling the letter “C”. Also called gap frame or overhanging press.

Source: The OHIO State University

A small carbide mill cutter usually one-half inch or less in diameter. Designed to remove stock from hardened tool steel.

Source: The OHIO State University

A device to move or do work at an angle to the press stroke.

Source: The OHIO State University

A motion at an angle to the direction of an applied force achieved by a wedge or cam.

Source: The OHIO State University

A block with one or more angular surfaces which applies force by the vertical movement of the press to mating angular surfaces on a cam slide. Also called driver.

Source: The OHIO State University

A mechanical press in which one or more of the slides are operated by cams; usually a double-action press in which the blankholder slide is operated by cams through which the dwell is obtained.

Source: The OHIO State University

A device to perform work at an angle to the press stroke. Most common angle is 900. Also called cam or slide.

Source: The OHIO State University

The tendency of material being sheared from sheet to bend away from the sheet in the same plane.

Source: The OHIO State University

(1) A dished distortion in a flat or nearly flat sheet metal surface, sometimes referred to as oil canning. (2) Enclosing a highly reactive metal within a relatively inert material for the purpose of hot working without undue oxidation of the active metal.

Source: The OHIO State University

A steel that owes its specific properties chiefly to the presence of carbon, without substantial amounts of other alloying elements. Also termed ordinary steel, straight carbon steel, or plain carbon steel.

Source: The OHIO State University

A process that introduces carbon into a solid ferrous alloy by heating the metal in contact with a carbon material, solid, liquid, or gas to a temperature above the transformation range and holding it at that temperature for a period of time.

Source: The OHIO State University

The area of a stock strip that ties the parts together and carries them through a progressive die until the final operation.

Source: The OHIO State University

Any process of hardening a ferrous alloy so that the case or surface is substantially harder than the core or interior.

Source: The OHIO State University

A solid reproduction of the outside surface of a part, detail, or model. Normally made of plaster. Used for spotting, machining, etc.

Source: The OHIO State University

A combined drill and countersink. The countersink is 60' included angle. Primarily used to drill center holes in the end of parts on the lathe and spotting centers of holes to be drilled.

Source: The OHIO State University

Machined or cast slots in the upper and lower die shoe and large adapters for handling purposes.

Source: The OHIO State University

A precision ground block which has a slot or hole on one surface and a leg off the opposite surface from the slot or hole. One surface of the leg is on the center line of the slot or hole. Used with an indicator to find the exact edge of a surface.

Source: The OHIO State University

(1) A beveled surface to eliminate an otherwise sharp corner. Usually about a 450 angle. (2) A relieved angular cutting edge at a tooth corner.

Source: The OHIO State University

A socket head cap screw with the head and the upper portion of the body turned down, leaving a minimum number of threads on the end of the body. Used where the screw hole in the detail does not align with the threaded hole in the mounting surface. Also called eberly screws, rubber screws, or kelly screws.

Source: The OHIO State University

The slope of the chord drawn between any two specific points on a stress-strain curve. See also modulus of elasticity.

Source: The OHIO State University

A trough in which blanks, workpieces, scrap, or parts are fed to or conveyed away from a die or press.

Source: The OHIO State University

A regular pattern of circles, [2.5mm(0.1in.) diameter], marked on a sheet metal blank.

Source: The OHIO State University

“A technique of measuring strains on deformed sheet steel. The result can then be plotted on the forming limit diagram” (Automotive Steel Partnership, 1991, p.2).

Source: The OHIO State University

The space, per side, between the punch and die. Also called breakage on trim and/or pierce dies. Space between any two details to avoid interference

Source: The OHIO State University

A combination coining and straightening operation performed in special cavity dies designed to impart a specific amount of working in specified areas of a forging to relieve the stresses developed during heat treatment.

Source: The OHIO State University

(1) A closed-die squeezing operation in which all surfaces of a workpiece are confined or restrained, resulting in a well-defined imprint of the die on the work. (2) A restriking operation used to sharpen or change an existing radius or profile. Coining can be done while forgings are hot or cold and is usually performed on surfaces parallel to the parting line of the forging.

Source: The OHIO State University

The initial development of a blank or part on paper or in wax during the designing of a die.

Source: The OHIO State University

The process of upsetting the ends of a bar, wire or tube stock while cold.

Source: The OHIO State University

A mill product produced from a hot-rolled pickled coil that has been given substantial cold reduction at room temperature. The usual end product is characterized by improved surface, greater uniformity in thickness, and improved mechanical properties as compared with hot-rolled sheet.

Source: The OHIO State University

The plastic deformation of metal under conditions of temperature and strain rate that induce strain hardening. Usually, but not necessarily, conducted at room temperature. Also referred to as cold forming or cold forging. Contrast with hot working.

Source: The OHIO State University

A four post single slide press.

Source: The OHIO State University

Any die designed to perform more than one operation on a part with one stroke of the press, such as blanking and piercing, in which all functions are performed simultaneously within the confines of the blank size being worked.

Source: The OHIO State University

The maximum compressive stress a material is capable of developing. With a brittle material that fails in compression by fracturing, the compressive strength has a definite value. In the case of ductile, malleable, or semi-viscous materials (which do not fail in compression by a shattering fracture), the value obtained for compressive strength is an arbitrary value dependent on the degree of distortion that is regarded as effective failure of the material.

Source: The OHIO State University

A stress that causes an elastic body to deform (shorten) in the direction of the applied load. Contrast with tensile stress

Source: The OHIO State University

Curvature of the peripheral edge viewed from outside of the part.

Source: The OHIO State University

A hole in which the center line is used to dimension other holes or surfaces. Sometimes referred to as a point of origin or coordinating hole.

Source: The OHIO State University

Machining surface shape on die members. Also called kellering.

Source: The OHIO State University

The forming of sheet metal into a series of straight, parallel alternate ridges and grooves with a rolling mill equipped with matched roller dies or a press brake equipped with specially shaped punch and die.

Source: The OHIO State University

Transverse ripples caused by a variation in strip shape during hot or cold reduction.

Source: The OHIO State University

A rotary, pilot guided, end cutting tool, having one or more cutting lips and usually having straight or helical flutes.

Source: The OHIO State University

Enlarging a hole to a limited depth producing a flat bottom in the enlargement.

Source: The OHIO State University

(1) A funnel shaped enlargement at the outer end of a drilled hole having an 820 included angle to allow the head of a screw to be flush with or below the surface. (2) A bit or drill for making a countersunk hole.

Source: The OHIO State University

A mechanical press whose slides are actuated by a crankshaft.

Source: The OHIO State University

A term used in a hemming operation for the amount the part reduces in size along the flange radius when forming from a 90 degree flange to a full fold or hem.

Source: The OHIO State University

The forming of relatively small corrugations in order to set down and lock a seam, to create an arc in a strip of metal, or to reduce an existing arc or diameter.

Source: The OHIO State University

Established temperatures to which metals must be heated to produce metallurgical changes, such as hardening. Also known as transformation temperatures.

Source: The OHIO State University

The physical area of a trim steel that overlaps the top of another trim steel, such as the area of an upper trim steel that is notched to go over the top of a lower scrap cutter. The distance between the two steels in this area, when die is closed, should be at least twice stock thickness.

Source: The OHIO State University

(1) The upper part (head) of a press frame. On hydraulic presses, the crown usually contains the cylinder; on mechanical presses, the crown contains the drive mechanism. See also hydraulic press and mechanical press. (2) A shape (crown) ground into a flat roll to ensure flatness of cold (and hot) rolled sheet and strip.

Source: The OHIO State University

(1) A sheet metal part; the product of the first drawing operation. (2) Any cylindrical part or shell closed at one end.

Source: The OHIO State University

A mixed-mode fracture, often seen in tensile test specimens of a ductile material, in which the central portion undergoes plane-strain fracture and the surrounding region undergoes plane-stress fracture. One of the mating fracture surfaces looks like a miniature cup; it has a central depressed flat-face region surrounded by a shear lip. The other fracture surface looks like a miniature truncated cone.

Source: The OHIO State University

(1) The first step in deep drawing. (2) Fracture of severely worked rods or wire in which one end looks like a cup and the other a cone.

Source: The OHIO State University

A mechanical test used to determine the ductility and stretching properties of sheet metal. It consists of measuring the maximum part depth that can be formed before fracture. The test is typically carried out by stretching the test piece clamped at its edges into a circular die using a punch with a hemispherical end. See also cup fracture, Erichsen test, and Olsen ductility test.

Source: The OHIO State University

The act of forming an edge of circular cross section along a sheet, workpiece, or at the end of a shell or tube.

Source: The OHIO State University

A method in which the part under fabrication is not entirely detached from the strip or is pushed back into the strip for transporting to a succeeding station in a progressive die.

Source: The OHIO State University

A pair of blades positioned in dies or equipment (or a section of the die milled to produce the same effect as inserted blades) used to separate the forging from the bar after forging operations are completed. Used only when forgings are produced from relatively long bars instead of from individual, precut multiples or blanks. See also blank.

Source: The OHIO State University