Size: 1/4" to 5/8" Nickel Plated nut size: M6*25 mm. be used in pipe and joint system products; pipe diameter is: 28.00mm; joint thickness is: 2.5mm.Nuts can be used widely in many fields.Automotive industry, electronic industry, semi-conductor industry, super market, warehouses, general factories, logistic operation, DIY stores, garden, school, hospital, pipe rack metal joint system, in facts, ...