2H

55' or 2-H may refer to:

Chemistry

• Deuterium, or ²H, an isotope of hydrogen
• 2H, a designation for chemicals with two hydrogen molecules
• 2H-pyran, a form of Pyran
• 2H-1-benzopyran, a form of Benzopyran
• 2H-pyran-2-one, a form of 2-Pyrone

Transport

• 2H, a type of Toyota H engine
• 2H, a type of Volkswagen EA827 engine
• Douglas O-2H, a model of Douglas O-2
• Chaparral 2H, a model of Chaparral Cars
• Aptera 2h, a model in the Aptera 2 Series
• SSH 2H (WA), alternate designation for Washington State Route 290

Other uses

• 2nd half of a fiscal year
• 2H, a harder grade of pencil lead

See also

• H2 (disambiguation)