# Geometric Dimensioning and Tolerancing for Mechanical Design

Topics: Geometric dimensioning and tolerancing, Datum reference, STEP-NC Pages: 108 (16142 words) Published: May 9, 2013
Geometric Dimensioning and Tolerancing for Mechanical Design Answer Guide
(Answers to the questions and problems at the end of each chapter)

Geometric Dimensioning and Tolerancing for Mechanical Design Answer Guide 2

Chapter 1 Introduction to Geometric Dimensioning and Tolerancing Chapter Review
Page 7 1. Geometric Dimensioning and Tolerancing is a symbolic language used to specify size , shape , form , orientation, the and

location

of features on a part.

2. Features toleranced with GD&T reflect the between mating parts.

actual relationship

3. Geometric Dimensioning and Tolerancing was designed to insure the proper assembly of mating parts , to improve quality , and reduce cost . 4. Geometric tolerancing allows the maximum available consequently, the most 5.

tolerance

and,

economical

parts.

ASME Y14.5–2009 is the current, authoritative reference document that specifies the proper application of GD&T. rectangular -shaped tolerance zone.

6. Plus or minus tolerancing generates a 7.

GD&T

generates a cylindrical-shaped tolerance zone to control an axis.

8. If the distance across a square tolerance zone is ± .005 or a total of .010, what is the ± .007 or .014 approximate distance across the diagonal? 9. Bonus tolerance equals the difference between the actual mating envelope size and the

maximum material condition
10. While processing, a rectangular part usually rests against a

.

datum

reference frame

consisting of three mutually perpendicular planes.

Geometric Dimensioning and Tolerancing for Mechanical Design Answer Guide 3

Chapter 2 Dimensioning and Tolerancing Fundamentals
Chapter Review
Page 15 1. 2. Each dimension shall have a tolerance except those dimensions specifically identified as reference, maximum, minimum, or stock. complete so there is a full Dimensioning and tolerancing must be understanding of the 3. 4.

characteristics interpretation define

of each feature. .

Dimensions shall not be subject to more than one The drawing should

the part without specifying methods.

manufacturing
5.

A 90° angle applies where center lines and lines depicting features are shown on a 2D orthographic drawing at right angles and no angle is specified. applies where centerlines of features in a pattern or surfaces shown at right angles on a 2D orthographic drawing are located or defined by basic dimensions and no angle is specified. All dimensions and tolerances are applicable at 68°F (20°C) unless otherwise specified. Measurements made at other temperatures may be adjusted mathematically. free state condition All dimensions and tolerances apply in the except for non-rigid parts. All tolerances apply for the

6.

A basic 90° angle

7. 8. 9.

full depth
, and

,

full length
unless otherwise specified.

full width

of the feature

drawing level 10. Dimensions and tolerances apply only at the where they are specified. 11. Units of linear measurement are typically expressed either in the inch metric 12. For decimal inch tolerances, a values less than one inch. system.

system or the

zero

is never placed before the decimal point for

Geometric Dimensioning and Tolerancing for Mechanical Design Answer Guide 4

13. For decimal inch tolerances, a dimension is specified with the same number of decimal . places as its tolerance 14. What are the two types of direct tolerancing methods?

Limit dimensioning and plus and minus dimensioning
15. For decimal inch tolerances, where a unilateral tolerance is specified and either the plus or the same number of decimal minus limit is zero, its zero value will have

places
as the other limit and the appropriate

plus and minus sign

.

16. For decimal inch tolerances, where bilateral tolerancing or limit dimensioning and have the same number of decimal places tolerancing is used, both values 17. Dimensional limits are used as if an infinite followed the last digit after...