What is "h-bar"

H-bar or h-bar can refer to:

• H with stroke, a Latin letter H with a doubled horizontal stroke (Ħ ħ)
• reduced Planck constant, which the above symbol represents as a mathematical symbol, ħ = h/(2π)
• Antihydrogen, an antimatter element represented by the symbol
• Steyr AUG H-bar, the light machine gun version of the AUG assault rifle