The lowest or basic strength of aluminum and each of its alloys is determined when the metal is in the annealed or soft condition. This is designated as the O (letter O) temper. For example, the annealed condition for alloy 1145 is written 1145-O.
What is a scissor lift? A scissor lift is a type of aerial work platform used to lift personnel. These platforms extend and retract vertically with the help of the scissor linkages that fold in a crisscross manner. Scissor lifts are typically electrically powered although there are some that are powered by internal combustion engines.
For sufficiently wide stairs, a rail is mounted to the treads of the stairs. A chair or lifting platform is attached to the rail. A person on the chair or platform is lifted as the chair moves along the rail. Stairlifts are known variously as stair lifts, stair-lifts, chair lifts, stair gliders and by other names. This type of chair lift should not be confused with the chairlift used by skiers. The term stair climber can refer either to stair lifts, or more commonly to the exercise equipment by the same name. Some of the first stairlifts to be produced commercially were advertised and sold in the USA in the 1930s by the Inclinator Company of America. Many users at the time were victims of polio.