Controls: Location of mechanical datums, the distance between optical surfaces, or a combination of the two
Related Terms: Center Thickness (CT), Sagitta (Sag), Outside Diameter (OD), Overall Height (OAH)
Units: Linear units
Specification Must Contain: Nominal value and linear tolerance
Optimax Preferred Specification: Directly measured quantities
Reasons: Directly measured quantities offer the best chance for repeatable measurements with minimal error sources
Manufacturing Standards: MIL-STD-34, ISO 10110-1
![Mechanical Attributes – Diameter, CT and Sag/OAH](https://optimaxsi-com.dev.webhost.io/wp-content/uploads/Mechanical-Dimensions-1024x493-1.png)