Thread: Thermal shrink fit

Hello Phil,
Yes, I think you may be (almost certainly are) correct. I just remember a fitter at work saying one thou. to the inch but I don't remember if he was talking about press fit or shrink fit. My little Engineers Black Book has the information, but I cannot comprehend what it means.

Russell

Hi Russell,
I have always used 1 thou per inch of diameter for press fit (as a rule of thumb).
I once had to shrink fit a stub gear to a 3" shaft. This gear drove the barrel on a cement truck. The interference for the 3" shaft was 5 thou. There was no key or locking screws in the gear just purely a shrink fit. 8 years later it is still driving the barrel and hasn't moved at all.

Phil