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[ptc-1690766]

Hi,

i have difficulty in finding the formula for contact radius in context to press fit.

A shaft is press fit into a smaller hole with the interference of "i". i want to know what would the the radius of the shaft/hole after assembly
i also don't know the contact pressure.

[ptc-1368288]

On 7/25/2009 10:50:50 PM, muraligouthaman wrote:
>Hi,
>
>i have difficulty in finding
>the formula for contact radius
>in context to press fit.
>
>A shaft is press fit into a
>smaller hole with the
>interference of "i". i want to
>know what would the the radius
>of the shaft/hole after
>assembly
>i also don't know the contact
>pressure.
______________________________

A pure question out of the blue that a machinist will answer immediately from standards and applicable codes, but all depending upon the accuracy of the machining. A common press fit is Dia (Hole) = Dia(shaft), hard to push. For tighter press fit: heat hole ... if not practical: cool shaft like soak in liquid nitrogen. Liquid nitrogen under evaporation (no residual air) is pretty inert.

How come if you are into that you have no knowledge ? Press fit goes by client specs or "art of the trade", you better ask a professional ... visit the web.

jmG

[TheodoreM.Bones]

Haw, Haw! In the old days of steam railroad locomotives, the tires were heated and slipped on the massive locomotive wheel rims and allowed to cool giving a real tight, strong fit proof against the multi-ton loads on the railroad tracks underneath. If the fit was too tight the tires might crack under stress later. You have to go by experience on these problems. No tables available.

[ptc-1214470]

Find a copy of Machinery's Handbook - it has pages of information and tables on the subject of push, forced, press, and interference fits of various materials.
Jim S.