Staking is the process of connecting two components by creating an

interference fit An interference fit, also known as a pressed fit or friction fit is a form of fastening between two ''tight'' fitting mating parts that produces a joint which is held together by friction after the parts are pushed together. Depending on the am ...

between the two pieces. One workpiece has a hole in it while the other has a

boss Boss may refer to: Occupations * Supervisor, often referred to as boss * Air boss, more formally, air officer, the person in charge of aircraft operations on an aircraft carrier * Crime boss, the head of a criminal organization * Fire boss, a ...

that fits within the hole. The boss is very slightly undersized so that it forms a

slip fit Engineering fits are generally used as part of geometric dimensioning and tolerancing when a part or assembly is designed. In engineering terms, the "fit" is the clearance between two mating parts, and the size of this clearance determines whether ...

. A staking punch is then used to expand the boss radially and to compress the boss axially so as to form an interference fit between the workpieces. This forms a permanent joint.Degarmo, pp. 415–416.

Thermoplastic staking

Thermoplastic staking, also known as heat staking, is the same process except that it uses heat to deform the plastic boss, instead of

cold forming In metallurgy, cold forming or cold working is any metalworking process in which metal is shaped below its recrystallization temperature, usually at the ambient temperature. Such processes are contrasted with hot working techniques like hot roll ...

. A

plastic Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptab ...

stud protruding from one component fits into a hole in the second component. The stud is then deformed through the

softening In physics and astronomy, an ''N''-body simulation is a simulation of a dynamical system of particles, usually under the influence of physical forces, such as gravity (see ''n''-body problem for other applications). ''N''-body simulations ar ...

of the plastic to form a head which mechanically locks the two components together. It is a versatile technique benefiting from being quick,

economical An economic system, or economic order, is a system of production, resource allocation and distribution of goods and services within a society or a given geographic area. It includes the combination of the various institutions, agencies, entities ...

and consistent. Unlike

welding Welding is a fabrication (metal), fabrication process that joins materials, usually metals or thermoplastics, by using high heat to melt the parts together and allowing them to cool, causing Fusion welding, fusion. Welding is distinct from lower ...

techniques, staking has the capacity to join plastics to other materials (e.g.

metal A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typicall ...

PCB PCB may refer to: Science and technology * Polychlorinated biphenyl, an organic chlorine compound, now recognized as an environmental toxin and classified as a persistent organic pollutant * Printed circuit board, a board used in electronics * ...

's) in addition to joining like or dissimilar plastics, and it has the advantage over other mechanical joining methods in eliminating the need for consumables such as

rivet A rivet is a permanent mechanical fastener. Before being installed, a rivet consists of a smooth cylindrical shaft with a head on one end. The end opposite to the head is called the ''tail''. On installation, the rivet is placed in a punched ...

s and

screw A screw and a bolt (see '' Differentiation between bolt and screw'' below) are similar types of fastener typically made of metal and characterized by a helical ridge, called a ''male thread'' (external thread). Screws and bolts are used to fa ...

Technology

Thermoplastic staking can be performed with a wide variety of technologies including: * Thermal Tooling * Thermal Punch (or Hot Punch) * Hot Air Cold Upset * Ultrasonic Staking * Cold Forming * Infrared Staking * Impulse Staking

Thermoplastic staking

Technology

References

Bibliography

Further reading