What is "lehr"

n. A long oven or kiln, often having a moving belt, used for annealing glass.

Lehr may refer to:

• Lehr (glassmaking), a kiln for annealing glass
• Lehr (surname)
• Lehr, North Dakota, U.S.
• Lehr Infantry Battalion of the Prussian and Imperial German Armies, 1819–1914
• Lehr Infantry Regiment of the German Army in World War I
• Lehr-Brigade (mot.) 900, a German Army brigade during World War II
• Panzer Lehr Division, a German armored division during World War II
• Lehr, a district of Ulm, Germany

A lehr is a temperature-controlled kiln for annealing objects made of glass. The name derives from the German verb lehren meaning to teach.

Rapid cooling of molten glass generates an uneven temperature distribution in the body of the glass which results in mechanical stress sufficient to cause cracking before the object has reached ambient temperature, or to result in susceptibility to cracking in later use, often resulting from thermal shock. To prevent this, objects manufactured from molten glass are annealed by cooling gradually in a lehr from a temperature just below the solidification point of the glass. Anneal cooling rate depends on the thickness of the glass, and can range from several tens of degrees Celsius per hour for thin sections to a fraction of a degree Celsius per hour for thick slabs or castings.

In glass manufacture, a lehr is typically a long kiln with a temperature gradient from end to end, through which newly made glass objects such as glasses or vases are transported on a conveyor belt. However, the same effect can be obtained in a small kiln by controlling the cooling rate with an electronic temperature controller.

Lehr is a surname. Notable people with the surname include:

• Anna Lehr, American silent film actress
• Clarence Lehr (1886–1948), American baseball player
• Devon Lehr, American television writer and screenwriter
• George W. Lehr (1937–1988), American politician from Missouri
• Henry Solomon Lehr (1838–1923), American educator, founder of Ohio Northern University
• Henry Symes Lehr (1869–1929), American socialite
• John Lehr (born 1967), American actor
• John Lehr (photographer) (born 1975), American photographer
• John C. Lehr (1878–1958), American politician, U.S. Representative from Michigan
• Justin Lehr (born 1977), American baseball pitcher
• Lew Lehr (1895–1950) American comedian, writer and editor
• Marguerite Lehr (1898–1987), American mathematician
• Matt Lehr (born 1979), American football player
• Robert Lehr (1883–1956), German politician
• Stanford Lehr (1912–1992), American politician, member of the Pennsylvania House of Representatives
• Ursula Lehr (born 1930), German politician and academic
• Zella Lehr, American singer and entertainer

Category:German-language surnames Category:Jewish surnames