Aluminium ball-joint handrail specification 1) Ball-joint rail have advantages such as attractive appearance, convenient installation, robustness, and good anti-corrosive property after oxidation. It is widely used in such industrial and construction engineering fields as electric power, petrochemicals, machinery, sewage treatment plant, waterworks, gardens, municipal roads, airports and wharfs. Style Ball diameter Column pipe diameter Handrails diameter Knee rail pipe diameter standard 76mm 50.0mm 48mm 40mm 2) in the table, the material is aluminium, if the material is stainless steel, we can produce them as for your require. 3) Rail height: single rail manufactured according to design, double rail is 1,100mm, and triple rail is 1,200 mm. 4) Column spacing: mainly four kinds as 1000mm,1200mm,1500mm,2000mm. 5) aluminium tube's size: subject to the design drawings confirmed by both parties.