Pin Force
Pin Force
(OP)
Hello
I'm trying to determine the minimum and maximum force that we can expect in lbs measured after we press a pin into a hole.
The pin is .0582/.0578 Dia x .1 long 420 SS ground finish
The hole is .0579/.0574. 17-4 stamped in .055/.053 thick material 50/50 shear to break
No lubrication.
Averag Poissons ratio for steel at .288 ?
Coefficient of friction .8 ?
E 30,000,000 ?
Our customer is looking for something like 50 lbs min but I need to find out how to calculate the min and max with the given tolerance stack. Any help would be greatly appreciated. - Rich
I'm trying to determine the minimum and maximum force that we can expect in lbs measured after we press a pin into a hole.
The pin is .0582/.0578 Dia x .1 long 420 SS ground finish
The hole is .0579/.0574. 17-4 stamped in .055/.053 thick material 50/50 shear to break
No lubrication.
Averag Poissons ratio for steel at .288 ?
Coefficient of friction .8 ?
E 30,000,000 ?
Our customer is looking for something like 50 lbs min but I need to find out how to calculate the min and max with the given tolerance stack. Any help would be greatly appreciated. - Rich





RE: Pin Force
Here are some formula that might help:-
Pa= f*3.142*d*L*Pc
where f=friction coefficient
Pc=contact pressure between the two members
d= nominal shaft dia
L=length of external member.
Pa= axial force required to interference fit
to calculate Pc for a given interference use the formula:-
Pc=x/[Dc*[((Dc^2+Di^2)/(Ei(Dc^2-Di^2))+....................
((Do^2+Dc^2)/(Eo*(Do^2-Dc^2))-((Ui/Ei)+
Ui/Eo))]
where x = total interference
Dc=dia of shaft
Di = dia of inner member(this is zero for solid shaft)
Do= outside dia of collar
Uo=poissons ratio for outer member
Ui=poissons ratio for inner member
Eo=modulus of elasticity for outer member
Ei=modulus of elasticity for inner member
This formula for Pc will simplify if the materials are the same.
Hope this helps
regards desertfox
RE: Pin Force
Machinery's Handbook has an excellent article on press fit vs shrink-fit calcl's and resulting forces to remove pin.
RE: Pin Force
Thankyou
RE: Pin Force
RE: Pin Force