1. What is meant by GD&T ?
Geometric Dimension & Tolerance (GD&T) is a system for defining engineering tolerances. GD&T is very important part of mechanical product design.
GD&T defines degree of accuracy and precision required on controlled feature of part. GD&T is used to define the nominal (theoretically perfect) geometry of parts and assemblies, to define the allowable variation in form and possible size of individual features, and to define the allowable variation between features.
2.Describe how you go about calculating feeds and speeds and how you determine cut depths and cut widths for a particular operation.
Everyone has their own ideas on this one (what, everyone doesn’t use G-Wizard Calculator?), so your goal is to see how compatible the applicant’s approach is with what your shop needs. We’ve got an article on how to optimize Cut Depth and Cut Width for 2 1/2D machining. When you’re 3D profiling the rules change (does your applicant know the strategies for both?). CAM developer Robert Grzesek wrote a fabulous guest post for us on how to choose your stepover for 3D work.
Don’t be afraid to drill down and ask about subjects like High Speed Machining or Chip Thinning if it looks like a productivity way to explore your applicant’s deeper skills set.
3.Why is GD&T and Why it is Important
4.What is Form Control in GD&T
Form tolerances are applicable to single (individual) features or elements of single features. Form tolerances are not related to datum.
5.When to use GD&T
6.What is Profile Control of GD&T?
7.What is meant by TERMINOLOGY REVIEW of GD&T
8. What is Tolerance in GD&T?
Tolerance.The total amount by which a specific dimension is permitted to vary. The tolerance is the difference between the maximum and minimum limits. They are three types:
9.What is Limits Of Size of GD&T?
A variation in form is allowed between the least material condition (LMC) and the maximum material condition (MMC).
The actual size of the feature at any cross section must be within the size boundary.
No portion of the feature may be outside a perfect form barrier at maximum material condition (MMC).
10.What is meant by Datum in GD&T
A theoretically exact point, axis, or plane derived from the true geometric counterpart of a specified datum feature, A datum is the origin from which the location or geometric characteristics of features of a part arc established.
11.What are Characteristics & Symbols cont’d in GD&T?
Maximum Material Condition MMC
12.What is Geometric Tolerance?
The general term applied to the category of tolerances used to control form, profile, orientation, location, and runout.
13.What is Feature Control Frame?
14.What is Bilateral Tolerance?
A tolerance in which variation is permitted in both directions from the specified dimension.
15.What is Unilateral Tolerance?
A tolerance in which variation is permitted in one direction from the specified dimension