According to the the form, fit and function of a part, tolerance is defined by the designer as the acceptable range for a dimension. Unless specifically marked or defined by the customer, the standard tolerance used by Shank is +/-0.1mm/0.005” for metal parts and +/- 1mm/0.010” for plastic parts. If tighter tolerances (less than the standard, e.g. +/-0.05mm/0.002”) are required, the information must be communicated or annotated on the drawings as to which dimensions need a narrow range. For reference, a piece of paper is about 0.07mm/0.003” thick.
It is important to remember that a tighter tolerance will result in additional cost because of increased scrap, additional fixture, special measurement tools and/or longer cycle times caused by the machines. They need to be slowed down to hold the tighter tolerance. Depending on the tighter tolerance and the geometry associated with it, costs could be more than double than holding the standard tolerance.If it is not necessary to use the tight tolerance, It will be better to use the standard one.
Overall geometric tolerances can also be applied to the drawing for the part. Based on the geometric tolerance and type of tolerance applied, additional cost may be the required because of increased inspection times.
To minimize the cost, the best way to apply tolerances is to only apply tight and/ or geometric tolerances to critical areas.
Shank Precision Machining Parts Co., Ltd was founded in 2005, which is Chinese professional manufacturer of all types of machining parts since 2005, supply quality products at competitive prices. We would like to be your reliable supplier and trusted friends. Thank you for your attention!
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