crowbar; pry bar
A heavy iron bar used for prying or demolition. The most common meaning in everyday Japanese.
from English bar
I used a crowbar to pry the door open.
Scientific/technical unit of pressure. Not commonly used in daily conversation.
The tire pressure is set to 2.2 bar.
The burglar pried the door open with a crowbar and broke in.
The culprit struck the man with a crowbar.
バー sounds similar but usually means a drinking bar, a bar-shaped fixture, or the symbol '-', whereas バール specifically means a crowbar or the pressure unit.
A バール (crowbar) is counted with 本 as a long, rod-shaped object.
For hand-held tools and implements — knives, razors, guns, candles, some instruments.
From English 'crowbar' (sense 1) and 'bar' as a unit of pressure (sense 2).