Chapter O: O Oxygen Free Copper

O

Symbol for the element oxygen.

?, ?

See also omega (?, ?).

oblique triangle

A common name for both acute triangles and obtuse triangles.

obtuse angle

If the inclination of the arms of an angle are more than a right angle (90 but less than a straight line 180 , also known as a straight angle since it corresponds to a rotation through half a full circle), the angle is called obtuse.

obtuse triangle

A triangle having one angle larger than 90 . Both obtuse- and acute-angled triangles are known under the common name of oblique-angled triangles. The sum of the three angles in every triangle is 180 .

OD

Abbreviation for outside diameter.

OEM

Abbreviation for Original Equipment Manufacturer.

oil bath tempering

A heat-treatment process whereby the work is immersed in oil heated to the correct temperature depending on type of steel, carbon content of the steel, hardness required, and toughness required. It is important that the temperature of the oil be uniform throughout and that the work be immersed long enough to reach this temperature. The best method for tempering is to submerge the work before heating the oil, so that it is heated along with the oil. After the pieces tempered are removed from the oil bath, they should be immediately dipped in a tank of caustic soda, followed by a bath of hot water. This final step will remove all oil that might adhere to the work. Used extensively for tempering steel...