Cold Headed Parts Types and Terms

  • Cold formed steel refers to any steel components fabricated by the cold forming process.
  • Cold forming is a process through which small, simple parts are produced by applying high pressure instead of heat.
  • Cold headed bolts (http://www.industrial-bolts.net) are some of the most common parts that are made using cold headed metal forming processes. These, along with screws and pins, make up the bulk of cold headed fasteners.
  • Cold headed fasteners are connective mechanisms, like screws, manufactured by the cold heading process.
  • Cold headed pins are made by manufacturers of cold headed parts. These pins have a head that is formed and shaped using the punch and die process.
  • Cold headed rivets hold together materials by spreading the tip via hammering and protruding through the material.
  • Cold headed screws can be made using a wide range of metal alloys. The use of a screw driver or allen wrench is necessary for securing this type of threaded fastener.
  • Cold heading is the process by which the heads of small, simple parts-like screws and bolts-are produced.
  • Impact extrusion is a cold forming process that produces collapsible tubes out of soft metals through impact with a punch, or ram.
  • Steel pins are fasteners made from steel wire that is sharpened at one end and headed at the other.

Anti-Seize Compound - A compound used on the thread of fasteners to prevent the galling of mating surfaces and improve corrosion resistance so the parts can be disassembled later.
 
Bearing Stress - The stress that is applied by a fastener to a joint face.
 
Chatter - Surfaces that are rough or otherwise unsatisfactory, caused by a slight jumping of the tool away from the work or the other way around.
 
Clamping Force - The force that is exerted on the joint by the fastener.
 
Clench - A fastener's ability to hold together previously separated materials.
 
Cold Work - The process of deforming metal at room temperature by hammering, drawing or forming.

Concentricity - The condition in which two fastener surfaces share the same center.

Creep - The permanent deformation of a fastener resulting from the application of stress and heat.

Die Impression - The portion of the die surface that shapes the forging.

Eccentricity - The degree of difference between the centers of a fastener's surface at different points.

Extrusion - The process of forcing metal to flow through a die orifice in the same direction in which energy is being applied (forward extrusion) or in the reverse direction (backward extrusion), in which case the metal usually follows the contour of the punch or moving forming tool.

Fatigue Strength - A fastener's fracture resistance ability during subjection to variations of stress.

Heading - The manipulation of wire, rod or bar stock in dies to form parts that generally contain portions that are greater in cross-sectional area than the original wire, rod or bar. Basically, heading is the creation of a head on a metal part via cold form molding.  
 
Impression - A cavity, or series of cavities (multiple), machined into a forging die to produce a desired configuration in the workpiece during forging.
 
Insert - A piece of steel that is tightly fixed in a die. The insert may be used to fill a cavity, to replace a portion of the die with a grade of steel that is better suited for service or to function as a small die with the impression fastened to a master die.

Joint - The material(s) that the fastener connects together.

Lead Thread - A measurement indicating the length between the beginning of a thread and the point at which the thread reaches its fullest size.
 
Overtapping - The process of tapping a thread after plating so that its tolerances will comply within specification and allow the internal and external threads to assemble.

Pitch - The distance between two threads.
 
Preload - The immediate tension of a fastener after tightening, which will reduce over time.

Ram - The main reciprocating member of a press, guided in the press frame, to which the punch or upper die is fastened.

Shank - The part of the fastener body between the head and the threaded portion.