Handrail

A handrail is a rail that is designed to be grasped by the hand so as to provide stability or support. Handrails are commonly used while ascending or descending stairways and escalators in order to prevent injurious falls. Handrails are typically supported by posts or mounted directly to walls.

Similar items not covered in this article include bathroom handrails — which help to prevent falls on slippery, wet floors — other grab bars, used, for instance, in ships' galleys, and barres, which serve as training aids for ballet dancers. Guard rails and balustrades line drop-offs and other dangerous areas, keeping people and vehicles out.

The oldest known handrail was uncovered by French archaeologist Pierre St. Jamaine in an Assyrian ruin in southern Iraq in the city-state Nippur.

British Standard and British Standard Code of Practice are harmonized to European Normal (EN) series. Handrail height is set between 0.9 - 1 metre. Further details may be found on the UK government website and the downloadable leaflet Technical Booklet H2006.

Various model codes—The International Code Council (ICC) and National Fire Protection Association (NFPA)—and accessibility standards—ANSI A117.1 and the Americans With Disabilities Act Standards for Accessible Design (ADA SAD)—refer to handrail dimensions. Current versions of these codes and standards now agree that handrail is defined as either a circular cross section with an outside diameter of 1¼" (32 mm) minimum and 2" (51 mm) maximum or a non-circular cross section with a perimeter dimension of 4" (100 mm) minimum and 6¼" (160 mm) maximum and a cross section dimension of 2¼" (57 mm) maximum. In addition, the International Residential Code (IRC) includes a definition of a "Type II" handrail that allows for handrail with a perimeter dimension greater than 6¼" (160 mm).

...
Wikipedia