BS 4500:2009 pdf free download.Limits and fits. Guidance for system of cone (taper) fits and tolerances for cones from C = 1:3 to 1:500, lengths from 6 mm to 630 mm and diameters up to 500 mm.
This British Standard gives guidance on a system of cone fits and tolerances for cones from C=1: 3 to 1: 500 and lengths from 6 mm to 630 mm.
The appropriate tolerances of this British Standard can also be used for prismatic workpieces, for example wedges.
This British Standard applies to cones which are dimensioned and toleranced according to BS ISO 3040, Method 1, Basic Taper method This means that the tolerances limit the variation of penetration of mating surfaces, each surface being within two limiting profiles of the same taper corresponding to the maximum material condition(MMC) and the least material condition (LMC).
This British Standard is derived from BS EN 20286, and is a complement to BS EN SO 1119.
NOTE: For dimensioning and tolerancing cones on drawings, see BS ISO 3040.
A special feature of cone fits is that clearances and interferences are made by defining the axial position of the assembled internal and external cones with respect to each other. The conical workpieces to be assembled are manufactured separately according to the tolerance zones indicated for their common basic cone diameter. Because of the methods of manufacture, a hole basis system of fits is recommended.
The axial position of the conical workpieces with respect to each other for obtaining the required clearance or interference of the cone fit in the final position of the assembled conical Workpieces can be made b different methods.
4.2 Constructional formation
This is a cone fit resulting from the constructional formation of the workpieces to be assembled (see Figure 17).
The axial position of the cones relative to each other in the final position (see 3.6.6) is determined by the form of the conical workpieces Figure 17 shows a clearance cone fit in which the workpiece with the external cone has a collar which contacts the surface of the workpiece with the internal cone. This type of construction is also valid for an iterference cone fit when the workpiece with the internal cone is pressed on to the workpiece with the external cone in order to make contact at the collar.