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.

Projected Tolerance Zone (#5)

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

PDF available for premium site members.

The Projected tolerance zone modifier is generally used for threaded holes and holes that will receive a pin (usually a press fit) and the designer is concerned that the screw or pin projecting from the hole might interfere with the surface of the clearance hole in the mating part. In these cases, it is more important to know where the stud or fastener will be rather than where the hole or tapped hole is [Y14.5M-1994 Para 5.5.2, Y14.5-2009 Para].

The projected value is usually the maximum thickness of the mating part or the maximum height of the pin or stud.

The specified value for the projected tolerance zone is a minimum. The specified tolerance applies only to the projection of the hole indicated by the projected tolerance.

The symbol is placed in the feature control frame as of the 1994 Standard. Prior to this, the symbol was placed in a separate frame under the feature control frame. The amount the tolerance projected is usually written next to the symbol. For clarity, the direction and height of the projected tolerance may be indicated with a heavy chain line drawn closely adjacent to an extension of the center line of the hole.

This tip is in accordance with ASME Y14.5M-1994 and ASME Y14.5-2009.
This tip was originally released in October 1997.

Max the Tec-Ease mascot

Learn About Premium Today!

Back to Tips Tip added Oct 1997