The question is to classify each as to whether it is chiral or achiral:

a) a screwdriver

b) a baseball bat

c) a golf club

d) a tennis shoe

e) an ear

f) a woodscrew

g) a car

f) a woodscrew

g) a car

h) a hammer

I understand that you can use a plane of symmetry to determine if something is chiral or achiral (if it equally divides the two... it is achiral. I get that.). According to the solutions, a screwdriver, a baseball bat, and a hammer are achiral and everything else is chiral. I get the baseball bat and screwdriver since a plane of symmetry can equally divide those into two equal halves but why is a hammer achiral? I can't seem to understand that. If a golf club is chiral, I feel like a hammer would be too?

Also, why is a woodscrew not achiral. I feel like a plane of symmetry could equally divide it into two halves.

Please help me understand this.