4. Another common type of wrench that you will see around
the home is the allen wrench. When you think wrench,
these are not the image that pops into your head. They
are usually L or S shaped and the head fits into the top of a
nut (usually with a hexagon shape). The wrench is then
turned to tighten or loosen the nut. You will see these a
lot with bicycles, in-line skates, and probably at lot of
assemble it yourself furniture that you get at warehouse
or department stores. Oftentimes, these types of items
that require allen wrenches will come with them, included
with the rest of the hardware for the item, but you may
someday need to purchase some yourself. You can get
many different sizes available on a keychain for a relatively
small price.