Determining Conventional Lathe Machining Tolerance

The lathe machining tolerance can be determined as a factor or as a percentage of the nominal value. It can also be implied by numeric accuracy of the nominal value. The lathe machine tolerance can be symmetrical or asymmetrical. 

Things to Consider When Setting Tolerance

The main thing to consider when setting tolerances is how far the tolerance can go without it interfering with other outcomes of another process. A good set of tolerances does not mean that compliance with those tolerances will be accomplished. Production of all products will require some variation of input (and output). There are measurement errors in all measurements. All data within a tolerance is usually accepted equally. The best products have measurements which are right on point. The greater the deviation is from the target, the greater the loss will be. This is called quality loss function. Quality loss function is the underlying factor of another system referred to as 'inertial tolerance'.

Mechanical Component Tolerance

Dimensional tolerance is related to the mating of two mechanical components in mechanical engineering. E.g. If a bolt with 10 mm diameter is supposed to have sliding fit inside the hole, then the shaft may have a tolerance range from 9.964 to 10mm, and the hole may have a tolerance range from 10.04mm to 10.076mm. That gives a clearance fir of approximately 0.04mm.