Your Source for GD&T Training and Materials
GD&T Articles
Expanding a Standard
Y14.8 for the dimensioning and tolerancing of castings and forgings is extended to molded parts.
By Donald E. Day
March 2010 | mechanical engineering
SME has expanded the scope of its standard
for the dimensioning and tolerancing
of casting and forging technologies. Since
most of the principles apply equally well
to molded parts, the standard, Y14.8, has
been renamed "Castings, Forgings, and
Molded Parts." The standard includes recommendations
for the uniform description of features that are unique to
cast, forged, and molded parts, and for their inclusion on
engineering drawings and related documents. [Continue Article]
Geometric Dimensioning and Tolerancing
The Common Thread of a Multifunctional Design Team
Once the design team has performed their DFA/M analysis, it is essential to document the solutions. Old methods of dimensioning and tolerancing leave the engineering document open to interpretation. The national standard on Geometric Dimensioningand Tolerancing (ANSI Y14.5M-1982) provides a method of defining parts with one clear meaning. A review of the dimensioning and tolerancing of parts by the multifunctional team answers the questions related to reliability, tooling, inspection, function, etc. prior to release of the drawing. Numerous examples will be presented that illustrate how this approach has reduced costs and design time while improving quality. [Continue Article]
Save Money By Understanding Variance and Tolerancing
Manufacturing processes are inherently variable, which results in component and assembly variance. Unless process capability, variance and tolerancing are fully understood, incorrect design tolerances may be applied, which will lead to more expensive tooling, inflated production costs, high reject rates, product recalls and excessive warranty costs. A methodology is described for correctly allocating tolerances and performing appropriate analysis. [Continue Article]
Quality 101: Defining GD&T
Geometric dimensioning and tolerancing has been evolving for decades, and is now a crucial practice for manufacturers hoping to compete globally. [Continue Article]
Process Capable Tolerancing (PCT) Quality costs often consume some 25% of total revenues in manufacturing business. Even the quality leaders face intimidating quality losses. The vast majority of quality costs are failure costs that include rework, scrap, warranty, product liability claims and recall costs. In general, the cost of failure is the difference between the actual production costs and what it would cost if there were no failures. [Continue Article]
Meeting in Maple Lake Sets Manufacturing Standards
Decisions were being made in Maple Lake last week that will have an impact on manufacturing across the country and throughout the world. Those decisions are the result of a meeting hosted by John Rivers of Product Technologies Inc. for an American Society of Mechanical Engineers committee which sets the standards for casted, forged and molded parts. [Continue Article]
Engineering Masters Advanced GD&T
Over a year ago Universal Engineering implemented the ANSI 14.5M-1982 standards. At that time all Engineering personnel went through a 32-hour training course that covered the basis of Geometric Dimensioning and Tolerancing (GD&T). [Continue Article]
