BS ISO 3302-1:2014 pdf download.Rubber- Tolerances for products Part 1: Dimensional tolerances. 3.2.1 Depending on the circumstances, measurements shall be made using one or more of the following types of instrument. 3.2.1.1 For solid products, a micrometre dial gauge, the foot of which shall exert a pressure of 22 kPa ± 5 kPa for rubber of hardness equal to oi greater than 35 IRHD or of 10 kPa ± 2 kPa for rubber of hardness less than 35 IRHD as specified in ISO 23529 and ISO 48. 3.2.1.2 A suitable optical measuring instrument 3.2.1.3 Fixed gauges, for upper and lower limits appropriate to the dimensions being measured. 3.2.1.4 Other devices, including tape measures (with or without vernier), sliding calipers, and micrometre calipers. 3.2.2 All instruments shall be capable of measuring the dimension with an error within the tolerances specified. 3.2.3 In all measurements intended to be comparative, the same measuring device shall be used. 4 Tolerances For the purposes of this part of ISO 3302, nominal dimensions and tolerances are based on the R 5 and R 10 series of preferred numbers, respectively, In accordance with ISO 3. The dimensions of certain parameters of a particular product may not all require the application of the same class of tolerance. Dimensions of different parameters of the product on the same drawing can have different class tolerances applied to them. When drawings do not indicate a class tolerance, the largest tolerance given in the related table shall be applied. NOTE 1 Tolerances that are specified in this part of ISO 3302 in terms of a positive value and an equal negative value (e.g. ± 0,35) can also be expressed in terms of unequal positive and negative values, providing the difference between the two values remains the same. For example, ± 0,35 may also be expressed as or +0. or etc. NOTE 2 Special consideration of tolerances will be necessary for a vukanizate with a low hardness and a high tensile strength (e.g. natural rubber gum vulcanizate). 5 Mouldings 5.1 General The dimensional tolerances stated in this part of ISO 3302 may be wider than those used in some other engineering practice. The following considerations apply. a) All rubber shows some shrinkage when cooled after moulding, and for this is made in the mould design. The amount of shrinkage is dependent on the rubber type and the mix used, but also varies from...
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