Press-fit diametrical interference recommendations
Press-fit diametrical interference recommendations
(OP)
I have a 1095 Steel shaft and a ULTEM 1000 polyetherimide part press fit. Diametrical interference is about 0.04.
I got an on-line press-fit calculator, recommended by this website, and it states Diametrical interference is 0.001 typically.
We have a problem of the plastic part cracking, even before the thermal shock. Could it be because of the wrong Diametrical interference value, please?
Thank you.
I got an on-line press-fit calculator, recommended by this website, and it states Diametrical interference is 0.001 typically.
We have a problem of the plastic part cracking, even before the thermal shock. Could it be because of the wrong Diametrical interference value, please?
Thank you.





RE: Press-fit diametrical interference recommendations
.001 to .005 would probably be reasonable if you have a nice chamfer lead in on the Ultem piece. Any more than that and I'd worry about cracking. Ultem's some excellent material. Very strong, very good dimensional stability at very low and high temps.
James Spisich
Design Engineer, CSWP
RE: Press-fit diametrical interference recommendations
I agree with James' statement, .001-.005 inches is reasonable.
-Dustin
Professional Engineer
Certified SolidWorks Professional
Certified COSMOSWorks Designer Specialist
Certified SolidWorks Advanced Sheet Metal Specialist
RE: Press-fit diametrical interference recommendations
RE: Press-fit diametrical interference recommendations
This is a RELATIVE value: interference divided by the shaft OD. No inches.
Sorry, I thought it is clear without any units.
Thanks.
RE: Press-fit diametrical interference recommendations