What happens to a hole in flat metal plate expands on being heated?
The hole will get larger like it was filled. Think of a ring made of a small diameter cable, say 1/10 the diameter of the ring. Now, heat it up so that it expands 10%. The ring is now 10% larger diameter wise, and the cable is also 10% bigger in thickness. But this 10% increase in width of the cable only represents 1% of the ring diameter, not enough to take away the increase in the ring diameter.
