Your Source for GD&T Training
Based on The GD&T Hierarchy

Tec-Ease, Inc. provides the most comprehensive GD&T training and coaching in the industry. Our GD&T courses are designed to keep the participant interested and engaged, while having fun.

Your Source for GD&T Software
and Computer Based Training

Tec-Ease, Inc. software packages are designed to help train and offer continued support to companies and employees in the industrial manufacturing field.

We offer On-Site Courses,
Public Seminars,
Webinars and Computer Based Training.


You can Calculate a Cpk when MMC is Used (#52)

(In accordance with the ASME Y14.5-2018 standard)
(In accordance with the ASME Y14.5-2009 standard)
(In accordance with Y14.5M-1994 standard)

PDF available for premium site members.

Many believe that when MMC is applied to a geometric tolerance, hard gaging, must be used. Hard gaging does not provide variable data and therefore is often not desirable for process control. Also, many customers today require that production calculate the Cpk of the process. The application of MMC or LMC may be thought of as specifying a single limit for position.

This drawing, for example, only requires that the size and inner boundary (virtual condition) of the hole be verified. The virtual condition is a single limit requirement. The theoretical design size of the gage pin (1) is 8.0-0.2=7.8. The distance from the axis of the datum simulator to the surface of the gage (2) is 3.9 (7.8/2).

By using an indicator, which is mastered at 3.9 from the datum simulator, variable data may be collected. Recording the distribution of data relative to the inner boundary allows the calculation of the Cpk of the process.

This tip is in accordance with ASME Y14.5M-1994, Y14.5-2009 and Y14.5-2018
This tip was originally released in March 2002.

Max the Tec-Ease mascot

Learn About Premium Today!

Back to Tips Tip added Jul 2022