Which should be paid attention to when buying castor performance parameters?

Universal wheel, adjust the foot manufacturers caster type is also very much, so we choose casters specifications and styles, some parameters are important index. 1, elongation under the action of tension, the distance between the sample fracture line when the increase and the ratio of the initial range, expressed as a percentage. 2, used for measuring hardness rubber tyre and wheel core materials and other hardness, with shaw represented 'A' or 'D'. Compression strength in the process of compression test, the sample on the maximum compressive stress, mpa to bill for the unit. 3, under the weight of the deformation resistance under the long time heavy wheels flattens the site gets bigger, the test sample must be under static load, and then at the end of the compression time stated on the discharge load, the height of the wheel with location become table after compared with the original high percentage. 4, the impact strength materials from the violent impact of free falling weight imposed by performance. Inch/pound, ft/LBS or test temperature stamping work.