2H

10H or 2-H may refer to:


 * Deuterium, or ^{2}H, an isotope of hydrogen
 * 2nd half of a fiscal year
 * 2H lead, a type of lead in a pencil
 * 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, one model of Chaparral Cars
 * Aptera 2h, a model in the Aptera 2 Series
 * SSH 2H (WA), alternate designation for Washington State Route 290
 * 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
 * 2H, a harder grade of pencil lead