Assembly
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Press Fits
Did you know?
Press fits allow the mating of different materials such as
metal to plastic. The benefit of the press fit is that it
is easy to assemble, reduces labor costs, eliminates the need
for adhesives and will bond normally incompatible materials.
Typical application is to hold contacts or connectors in electrical
bases.
What is a press fit?
A press fit is a non-physical bond that joins parts through
a mechanical lock (see figure 1
below). This is not suitable for applications where a
hermetic seal is required.
Key design considerations:
- A press fit undergoes a significant
amount of stress continuously
- Long-term performance must be taken
into account as continuous stress may cause failure
- Chemical compatibility between
two materials
- Joint strength will be affected
by temperature and in turn will be affected by the
following properties:
a.
Flexural modulus
b.
Coefficients of thermal expansion
c.
Creep
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Stress Level Calculations
For a cylindrical interference press fit the contact pressure
is needed in order to calculate the stress levels.
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