Rules For Dimensioning

CDTD 130 Tool Detailing

CAD Drafting - Tool Design
Rules for Dimensioning Tooling Components

Objective:
Reduce confusion about the size, shape and location of features,
by providing proper notes and dimensions that clarify the information.

View selection for details should be exactly as the Tool layout views if possible.
Place dimensions in views where the shape and location of the object is seen
best.
        Circular features (especially Holes), Should , must be sized and located in the circular view.
        Locate and give the size of a slot in the same view.
        Give a distance and angle in the same view
Place dimensions off the object. (No dimensions to appear ON the object)
Stagger dimensions that are stacked.
Nothing is to interfere between arrows (No leaders to cross a dimension line)
Group dimensions together. Be sure to allow for spacing between views and dims.
Place dimensions a minimum of .50 inches from and object line, .4 thereafter.
Place the R in front of radius dimensions and, the diameter symbol (Ø) in front of diameter dimensions.

Place the diameter dimension with symbol in the rectangular view for a positive cylinder (outside diameter), and,
negative cylinders (holes) may be dimensioned in the circular view or on a sectioned view.
Use the times identifier for multiple entities. Example: (4) .12 X 30 deg.
Text for notes and dimensions should be .12 or .18 high. Select one size for ALL dimensions/text.
Title block text should be .08 to .12 high except for part numbers and part names which are .25 high.

Base line dimensioning or ordinate (0,0 Tool) dimensioning is preferred but a direct dimension may be required for functional purposes.
No more than two dimensions may be chained.
Do not double dimension. (This means providing dimensions that give you two different solutions for the same distance).

All dimensions have a tolerance, either local (attached to the dimension), in a note or general (tolerance block).
Never use a 4 place decimal unless approved by the design manager (Dowel holes are an exception).
Tolerances accumulate. This means when you add or subtract dimensions the tolerances accumulates (summed).

Use symbols for hole type (c'bore, c'sink), and depth.
Place general notes near the title block and number your individual notes.
No fractional dimensions will be used in tool detailing.
When baseline or ordinate dimensioning, dimension from a finished surface or machined center.
Place machined dimensions for a critical feature (Slip/Press fit).
Do not dimension to any hidden line. Exceptions will be explained.
Leaders start at the beginning or end of a note, and point to centers of features.
Tolerance between SHCS, DR /C'BORE and Tapped Holes shall be: +/- .005
Tolerance between Doweled Holes is +/- .0005

USE THE TEXT BOOK EXAMPLES WHEN YOU ARE NOT SURE OF HOW TO APPLY A DIMENSION.
ASME Y14.5M 1994 STANDARDS ARE USED.

Objective:
Reduce confusion about the size, shape and location of features,
by providing proper notes and dimensions that clarify the information.

View selection for details should be exactly as the Tool layout views if possible.

Place dimensions in views where the shape and location of the object is seen
best.
        Circular features (especially Holes), Should , must be sized and located in the circular view.
        Locate and give the size of a slot in the same view.
        Give a distance and angle in the same view

Place dimensions off the object. (No dimensions to appear ON the object)

Stagger dimensions that are stacked.

Nothing is to interfere between arrows (No leaders to cross a dimension line)

Group dimensions together. Be sure to allow for spacing between views and dims.

Place dimensions a minimum of .50 inches from and object line, .4 thereafter.

Place the R in front of radius dimensions and, the diameter symbol (Ø) in front of diameter dimensions.

Place the diameter dimension with symbol in the rectangular view for a positive cylinder (outside diameter), and,
negative cylinders (holes) may be dimensioned in the circular view or on a sectioned view.

Use the times identifier for multiple entities. Example: (4) .12 X 30 deg.

Text for notes and dimensions should be .12 or .18 high. Select one size for ALL dimensions/text.

Title block text should be .08 to .12 high except for part numbers and part names which are .25 high.

Base line dimensioning or ordinate (0,0 Tool) dimensioning is preferred but a direct dimension may be required for functional purposes.

No more than two dimensions may be chained.

Do not double dimension. (This means providing dimensions that give you two different solutions for the same distance).

All dimensions have a tolerance, either local (attached to the dimension), in a note or general (tolerance block).

Never use a 4 place decimal unless approved by the design manager (Dowel holes are an exception).

Tolerances accumulate. This means when you add or subtract dimensions the tolerances accumulates (summed).

Use symbols for hole type (c'bore, c'sink), and depth.

Place general notes near the title block and number your individual notes.

No fractional dimensions will be used in tool detailing.

When baseline or ordinate dimensioning, dimension from a finished surface or machined center.

Place machined dimensions for a critical feature (Slip/Press fit).

Do not dimension to any hidden line. Exceptions will be explained.

Leaders start at the beginning or end of a note, and point to centers of features.

Tolerance between SHCS, DR /C'BORE and Tapped Holes shall be: +/- .005

Tolerance between Doweled Holes is +/- .0005

Objective: Reduce confusion about the size, shape and location of features, by providing proper notes and dimensions that clarify the information.