Dimensioning and Tolerancing Flashcards

Flashcards based on lecture notes about dimensioning and tolerancing in engineering drawings.

What is the primary function of smart dimensioning in drawings?

It serves as the main axis for dimensioning.

What views are generally sufficient for dimensioning an assembly?

Top and front views, supplemented by an isometric view as needed.

What is a tangent edge in the context of drawings?

It occurs where a flat surface intersects or meets a curved surface.

What does the term 'associativity' refer to in the context of dimensioning?

Maintaining a link between the drawing dimensions and the original model.

Define 'tolerance' in the context of engineering design.

The acceptable range of variability that ensures a design performs as intended.

What is the main principle behind 'true' design?

Establishing the least restrictive dimension on parts that allows the device to perform as intended.

What is the significance of the AMSE Y14.5 standard?

It provides rules for the appearance of drawings, including font, dimensions, lines, arrows, placement, and spacing, to reduce misinterpretation.

What should be specified for every feature in a drawing?

Every feature must be fully dimensioned, leaving nothing to assumption.

What is the recommended usage of reference dimensions?

Use as few reference dimensions as possible.

How should dimensions be expressed for millimeters and inches?

Millimeters are expressed as a dimension range, while inches are expressed as decimal places.

Why is it important to dimension from and to the right places?

It expresses the best of the design intent.

What is a baseline dimension?

When all the vertical dimensions are relative to a horizontal line and vice versa.

What is a chain dimension, and what is its disadvantage?

Building dimensions on top of one another; it cumulates tolerance.

Which lines should be used for dimensioning?

Only visible lines, not hidden lines.

At what temperature do all dimensions apply, unless otherwise specified?

Room temperature (20 degrees Celsius).

What does 'free state condition' refer to?

An unstressed condition.

Why is it important not to add unnecessary zeros to dimensions?

It can make the manufacturing process unbuildable or almost unmanufacturable.

What is GD&T?

Geometric dimensioning and tolerancing, a technology developed to minimize ambiguity in graphical engineering communication.

What is the purpose of specifying datums in a particular order?

To establish precedence for how the part should be positioned during manufacturing and inspection.

What does the term 'bonus tolerance' refer to?

A situation where the least material condition is when the hole is the largest.

What are profile controls typically used for?

Surfaces that have curviness.

How is perpendicularity related to angularity?

Perpendicularity is angularity at 90 degrees.

What is the function of the Solidworks MDB tab?

It is used to annotate in the 3-D views.

What is an ANSI B4.1

US Standard

What is an ISO FIT

Metric Standard

What is allowance?

Minimum clearance or maximum interference (maximum material condition)

Describe the concept of a Hole Basis

Basic size is the smallest (hole can be larger), most commonly used - This is when the shaft depends on the hole

Define Shaft Basis

Basic size is the largest shaft (the shaft can be smaller) - For mating applications where the shaft “drives” the dimensions of mating components - This is when the hole depends on the shaft

Describe what a transitional fit is

Is a selective assembly Considerando whether it was a clearance or interference fit

What does RC stand for

Running Clearance Fit

What does LC stand for

Locational Clearance Fit

what does LT or LN stand for

Locational Transition or Interference Fit

What does FN stand for

Force Fit