Engineering Definitions

H

Handling Core

Cast cores in upper and lower shoes used for handling purposes.

Source: The OHIO State University

Handling Ring

A device bolted to the side of a mold die for handling of the mold.

Source: The OHIO State University

Heel Block

(1) A block or plate usually mounted on or attached to a lower die and serving to prevent or minimize deflection of punches or cams. (2) When heel blocks are used with a mating heel post, this assembly can be used alone or in conjunction with guide pins. This helps align the die to prevent damage when the press ram has too much play.

Source: The OHIO State University

Heel Plate

A wear plate used on the heel block. See also wear plate and heel block.

Source: The OHIO State University

Heel Post

A male member that has either a machined wear surface or wear plates mounted to it that mates with a heel block. It is incorporated in dies to hold the die alignment and absorbs lateral pressures produced within the die.

Source: The OHIO State University

Hem Die Plus

The amount of stock added to a part in an area to be hemmed to compensate for the amount the part reduces in size along the flange radius when hemmed.

Source: The OHIO State University

Hem Edge Roll

When the outer panel rolls up off of the hem die during the hemming process.

Source: The OHIO State University

Hem Flange Split

Usually observed in concave edge and concave surface flanging and hemming.

Source: The OHIO State University

Hem Out

Usually observed with wrinkling after flanging or pre-hemming. Severe wrinkles in convex edge hemming may develop hem-out.

Source: The OHIO State University

Hem Steel

The steel in a hem die that finishes and flattens the hem. Also called hammer steel.

Source: The OHIO State University

Hemming

A bend of 180' made in two steps. First, a sharp-angle bend is made; next, the bend is closed using a flat punch and a die.

Source: The OHIO State University

Hemming Die

A die which folds the edge of the part back over on itself. The edge may or may not be completely flattened to form a closed hem.

Source: The OHIO State University

Herf

A common abbreviation for high energy-rate forging or high-energy-rate forming.

Source: The OHIO State University

High Collar Lock Washer

A special type of lock washer that is thicker than standard and smaller in diameter than standard. Designed to fit in a standard counterbored hole for a socket head cap screw.

Source: The OHIO State University

HIgh Energy Rate Forming

A group of forming processes that applies a high rate of strain to the material being formed through the application of high rates of energy transfer. See also explosive forming and electromagnetic forming.

Source: The OHIO State University

Hold Down Plate

A pressurized plate designed to hold the workpiece down during a press operation. In practice, this plate often serves as a stripper and is also called a stripper plate.

Source: The OHIO State University

Hole Flanging

The forming of an integral collar around the periphery of a previously formed hole in a sheet metal part.

Source: The OHIO State University

Homing the Die

Adjusting press ram/slide so die is on bottom or on the stop blocks at the bottom of the press stroke. Also called bottoming the die.

Source: The OHIO State University

Hone

A fine grit stone used with a fluid for sharpening or smoothing a surface.

Source: The OHIO State University

Hone Bucket

A container which holds cleaning and lubricant fluids for wet hones. Also called minnow bucket.

Source: The OHIO State University

Hooke’s Law

A material in which the stress is linearly proportional to strain is said to obey Hooke's law.

Source: The OHIO State University

Horn

(1) Lower section of the die on which the part nests. Also called an adapter, boss, die post, locator, master, master plug, and stool. (2) A portion of the die or part that protrudes.

Source: The OHIO State University

Hot Developing

The development of a blank or part during the tryout of the die.

Source: The OHIO State University

Hot Shear

A term used for a quick fix of a trim steel that should only be done in an emergency situation. It is done by welding the steel and roughing it back close to the original surface. Next the steel is reheated until it becomes molten red and then the press is cycled to get the location of the mating surface. Die clearance must be added after this location is obtained.

Source: The OHIO State University

Hydraulic Press

A press in which fluid pressure is used to actuate and control the ram.

Source: The OHIO State University

Hydraulic Press Brake

A press brake in which the ram is actuated directly by hydraulic cylinders.

Source: The OHIO State University

Hydraulic Shear

A shear in which the crosshead is actuated by hydraulic cylinders.

Source: The OHIO State University