Definition - What does Shade Number mean?
Shade number is a number that indicates the amount of darkness provided by a particular lens used as an eye protector against intense light during arc welding and plasma arc cutting operations. This type of eye protection is used specifically to protect against retinal damage. Shade number is a guide used by welders to select the most comfortable, yet clear lens for a particular welding or cutting operation.
Safeopedia explains Shade Number
Shade numbers do not necessarily correspond to the level of protection that they provide to the eyes. A higher number does not provide better protection, but is darker. These filter lenses are made of special glass, and filter out 100% ultraviolet (UV) and infrared (IR) waves that are harmful to the eyes. Shade numbers range from 2 to 14.
There are suggestion charts for shade numbers. These charts suggest which one to be used for a particular operation to see the weld puddle clearly. These charts are based on welding process, size of electrode and arc current. However, the operators may have their own preferences.