There are two types of wrenches: open end and box end. Both types are
necessary for automobile maintenance and repair. The box end wrenches have a
better grip than the open end type, but the open end wrenches must be used in
some cases such as fuel and brake line work. The wrench head can be angled
from straight or 0º to right or 90º to make access to bolts and nuts easier.
The standard wrench offset is 15 to 30º. Box end wrenches in ratcheting
models are more efficient, but adjustable open end wrenches are also very handy.
More and more auto work requires Allen wrenches and Torx or star wrenches.
Allen wrenches are hexagonal. Torx bits are multi-serrated inserts fitting
inside a bolt or screw head.