Tolerance Notes

It is necessary today to hold precise tolerances to insure the interchangeability of parts
It's the process of determining the smount a dimension can vary from it's theorectical size

• Basic Size
• the exact theoretical size of a dimension
• Tolerance
• the amount a dimension can vary from basic size
• Feature
• used to identify the geometry of the drawing being referenced
• Limits
• the maximum and minimum allowable size
• Allowance
• the limits where the smallest clearance or largest interference occurs. Measured at MMC

Styles

• Limit Dimensioning
• Deviation Dimensioning
• Symmetrical Dimensioning

MMC

• (Maximum Material Condition)
• The limit of a dimension where the max material is left on the part

LMC

• (Least Material Condition)
• the limit of a dimension where the least amount of material is left on the part

Type of Fit

• Clearence (Running and Sliding Fit)
• all dimension combos will produce clearence between parts
• Interference
• all combos of dimensions will produce a force fit
• Transitional
• different combos of dimensions will produce different kinds of fits