The Precision Machined Products Associations Designers Guide is intended for use by those who prepare drawings of precision machined parts.
Too often drawings do not have all the information needed to produce the piece described. This Guide is aimed at eliminating “silent” prints by showing what has to be specified and how it should be specified on the drawing.
This Guide calls attention to the characteristics on a part which, if clearly specified on the drawing, will eliminate confusion, arguments, and rejected production.
This Guide is not intended to teach anyone how to draw blueprints, but will point out where part drawings all too often are vague. One safe rule to follow is leave nothing to chance or interpretation. Determine what is needed; then relay that information to your supplier by preparing a complete drawing. It will be mutually beneficial.
Note: The dimensioning and tolerancing practices used in this Guide follow the principles of ANSI/ASME Y14.5M, Dimensioning and Tolerancing. The latest revision of this standard, as well as other ANSI/ASME standards mentioned in this document, can be obtained from the American National Standards Institute.
DESIGNER’S GUIDE
TABLE OF CONTENTS
CHECK LIST FOR PART DRAWINGS
MATERIALS
Stock Size and Part Size
Materials and Finish
DIMENSIONS AND TOLERANCES
NOTES ON DRAWINGS
SURFACE TEXTURE (FINISH)
ACCEPTABLE QUALITY LEVELS (AQL)
OUTSIDE SURFACES
Intersecting Surfaces
External Sharp Corners and Intersecting Surfaces
Cutoff Burrs and Chamfers
Dimensioning
Concentricity and Squareness
Eccentricity
Spherical Radius
Outside Tapers
Flats
Slots
Keyways
Undercuts
Knurls and Serrations
Marking
INSIDE SURFACES
Internal Sharp Corners and Intersecting Surfaces
Intersecting Surfaces and Burrs
Inside Squares and Hexagons
Concentricity
Flat Bottom Holes
Recesses
Inside Tapers
THREADS
Specifying Threads
Thread Relief and Chamfers
Threads and Burrs
OTHER PROCESSES
SYMBOLS
REFERENCES AND SOURCES OF INFORMATION
DESIGN AND ENGINEERING AIDS
You can modify this structure using our intuitive drag and drop interface, which allows you to rearrange content to your heart’s content.
ig