Just for chit-chat – Lets say you have piece of 2” thick steel plate. You drill a 4” diameter hole into the plate, and you wish to insert a 4.002” diameter pin (for a 0.002" interference fit).
Cooling the pin with dry ice (-109 degrees F) will shrink it diametrically by 0.0048”, providing an overall insertion-clearance of 0.0028”. That’s not a lot. Obviously the bore must be completely free of any nicks, or burrs, or debris (hone it – clean it well). The pin must be in the same condition, or you will not be pushing the pin into the hole by hand. You must go quick – before it starts to adsorb heat.
Once inserted to a depth of 2 inches, and after the pin achieves room temperature, there will be approximately 7200 psi of compressive stress generated against the surface of the pin. Assuming a 0.2 friction-coefficient (typical for steel against steel), it will take approximately 36,191 pounds of axial force to push the pin from the hole. Or it would take approximately 6,032 foot-pounds of torque to cause the pin to rotate within the hole.
Why is this important? Let’s say your plate was 3 inches thick and you only got the pin interred 2” deep before it warmed up. Better have a big hydraulic press. The insertion force required at a depth of 3 inches is about 54,287 pounds. Required torque to cause rotation 9,408 ft-lbf.
And if you increase the diameter of the pin to 4.003” (an extra thousandths of interference). The insertion force required to achieve a depth of 3 inches becomes 81,430 pounds axial. Required torque for rotation becomes 13,572 ft-lbf.
However when the pin is properly chilled, you can insert & rotate by hand. . . . Obviously with heavy interference fits, it becomes clear why liquid nitrogen is the preferred cooling method. . .