Specifications typically give an OMC range of what tolerance?

• A. +/- 1%
• B. +/- 2%
• C. +/- 5%
• D. +/- 10%

Answer: (B)

Tolerances in specifications set how much a measured OMC value can vary from the stated nominal. A typical tolerance of plus or minus two percent is used because it strikes a practical balance between precision and constructability. With this level, you can still achieve reliable fit and performance in the field while avoiding the high costs and tight QA that come with tighter tolerances. For example, if the nominal OMC is 100 units, the allowable range is 98 to 102 units. A smaller tolerance like ±1% would be expensive and harder to achieve in practice, while larger tolerances (±5% or ±10%) could lead to misfits or degraded performance.