Force required for press fit 1

[pmainland]

Hello,
I am looking for some help in getting a ball park figure for a press fit. We are looking at high force linear servo motor from Rockwell to do the job. My problem is I'm not sure how much force is required. I have tried a few formulas I found on the web but the resulting answer was out of the ball park. I left the drawings at work but from what I can remember the details are:

Pin: .395" dia (solid), 303/304 S.S. .25 long

Mating hole: 12L14 steel, 52RC.

Maximum interference is .0018"

Any help would be greatly appreciated!!

 

[unclesyd]

As I have a problem thinking in metric, generally anything, here is another similar approach.

http://www.tribology-abc.com/sub23.htm

 

[dimjim]

From Unclesyd's reference:
The interference should be corrected for the effect of surface roughness. The flattening of roughness peaks by mounting under high pressure is generally estimated at 10% of the Rz-value where Rz=6Ra (ISO 6336-2). The correction at the diametrical interference thus becomes 0.1·2·(Rz1+Rz2). If the surface roughness of the shaft Ra1=0.5?m and that of the bore Ra2=1?m then d?=0.1·2·6·(0.5+1)=1.8?m and ?eff=?m-d? where ?eff=effective value of diametrical interference, ?m=measured value of diametrical interference and d?=correction for surface roughness.

Even so, it would not account for that amount of difference.

 

[GregLocock]

Thay've broke it

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[GregLocock]

electricpete your equation ignores the Poissons ratio correction. If I put nu=0.0 into my calculation I get 1190 lbf

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.