Just for accuracy and completeness, I'll mention that thermal expansion of materials is not a matter of being faster or slower, but more or less. The speed at which it occurs depends on the speed at which you change the temperature of the material. For example, it's common practice to remove a stuck steel nut on a steel stud by heating the nut with a torch. The nut and stud both have the same coefficient of thermal expansion, but the nut gets hot much faster than the stud. The resulting differences in thermal expansion help break bonds that have formed between the two making it easier to remove.
Here's a question for you. If you uniformly heat a part with a hole in it (like a nut for instance), does the hole get bigger or smaller?