Alex Krulikowski

Here’s a question we received last week…

I have been talking with some drafters and engineers about the standard and have heard varying answers. I’m wondering about when you state the ASME Y14.5-2009 Standard on your drawing in a note or in a title block what it actually means.

Ex. “INTERPRET DIMENSIONING AND TOLERANCING PER STANDARD ASME Y14.5-2009″

Does it mean that the print will always be dimensioned using GD&T?

Does it force you to only dimension using GD&T, or can you use the basic limit dimensioning style?

Does the basic limit dimensioning style still fall under that standard?

Brian Mebruer
Cooper Industries

Great question! People often wonder if invoking the Y14.5 Standard means that they can no longer use limit dimensions (some call it coordinate tolerancing). The Y14.5 Standard does allow the use of limit dimensions. Also, when specifying the Y14.5 Standard, it invokes Rule #1, which helps to clarify where limit dimensions are used as size dimensions.

However, the Y14.5 Standard discourages the use of limit dimensions for locating features of size (i.e. holes, widths, tabs, etc.).

Using limit dimensions for locating features of size has three major shortcomings:

1. The square (or rectangular) tolerance zones are overly restrictive.
2. The tolerance zones are always a fixed size.
3. There are no specifications for how to hold the part for measurement.

The first two shortcomings result in less tolerance for manufacturing. The third shortcoming of limit dimensioning is that it results in confusion or disputes over inspection results. The lack of datum specifications leaves the drawing with at least several interpretations.

I hope this helps.

Alex

Earlier this month, I blogged about my new geometric tolerancing book that explains the use of ISO standards on technical drawings:

It’s a comprehensive book that can be used to learn the topic, and it’s also a great reference guide. The book is based on ISO 1101-2004 and companion standards.

ETI is offering a course this fall that utilizes the new book. The ISO Geometrical Tolerancing 3-day workshop will be held September 29th – October 1st, here in the Detroit area. The three-day ISO workshop will help you to understand engineering drawings that use the International Standards Organization (ISO) standards.

The course was written with three goals in mind:
1. To help you recognize what is required on a good (standard-compliant) drawing
2. To help you understand geometrical tolerances based on the ISO standards
3. To combine and explain information from dozens of ISO standards into a logical understandable topic

You’ll learn about …

• ISO drawing conventions
• GPS basics
• Limits and fits
• The datum system
• Form controls
• Orientation controls
• Location controls
• Run-out and profile controls
• General tolerances
• Workpiece edges
• Surface texture
• How ISO compares to ASME

If your company is interested in global sourcing and learning how to read drawings created in other countries, this workshop is vital to your success. It will teach you the ins and outs of utilizing the ISO standards and will give you a fundamental knowledge of ISO 1101:2004, related standards, and their application on drawings.

Those who attend the workshop will receive:

• Alex Krulikowski’s ISO Geometrical Tolerancing Reference Guide
• An ISO Geometrical Tolerancing Workbook
• Class handouts
• An official certificate of completion

Read more about the course and specific topics here. I hope to see you in the Detroit area for this exciting new workshop.

The new ASME standard contains numerous changes that affect the specification and interpretation of tolerancing. Companies deciding whether or not to update to the new standard need to understand what has changed and how these changes will impact their product.

As one of the people involved in creating this new version of ASME Y14.5, I have developed a one-day “ASME Y14.5-2009 Update Workshop” that will teach you about the pertinent changes to the standard. This workshop covers over sixty significant revisions, additions, and deletions to the standard. I’ll explain new features and compare them to the 1994 Standard. As part of the course, you’ll receive a set of comprehensive, illustrated charts that highlight itemized changes in the standard.

This drawing shows a small percentage of the changes in the ASME Y14.5 Standard. Click to see the entire drawing.

I’ll explain the major changes to the standard, including:

• Over thirty new or revised terms
• Sixteen new or revised symbols
• Revisions and additions to the fundamental rules
• Revisions and additions to the concept of feature of size
• Revisions and new symbols for datum specifications
• Revisions to composite position tolerances
• Surface boundaries and axis methods of interpretation
• Revisions and new additions to profile tolerances

The ASME Y14.5 1994-2009 Update Course will help you to:

• Understand changes in the standard
• Learn about new symbols and how to apply them to drawings
• Determine the impact of the new standard

ETI can provide this training at your site, and it is also being offered as a public workshop in Michigan on Monday, September 28, 2009. The regular price of this workshop is $375; the first 20 registrants pay only $175.

Attendees must have a basic understanding of Y14.5-1994 Dimensioning and Tolerancing practices.

The new ASME standard contains numerous changes that affect the specification and interpretation of tolerancing. As one of the participants in the creation of the new standard, I will provide insights as to why the changes were made at a lecture on August 13th, from 9 am-12 noon, here in Michigan.

“A Quick Look at the ASME Y14.5-2009 Standard” is a short, 3-hour session about the new ASME Y14.5-2009 Standard. This update session will get you started in understanding the depth of the changes and new features, and it includes a discussion about when it makes sense to implement the new standard. Topics covered include:

• The ASME standards development process
• Introduction to new and revised terms
• Introduction to new and revised symbols
• Synopsis of major changes and why they were made
• Discussion on implementing the new standard
• Questions/answer session

The regular price of this workshop is $50, but the first 20 people to purchase my white paper/comparison chart package for $30 can attend for free.

A few months ago, I created a survey asking whether companies plan to adopt the new Y14.5-2009 standard, stay with the 1994 standard, or change to ISO standards. Using statistics elicited from the survey responses, I have developed a white paper addressing these issues.

“Deliberations on Dimensioning and Tolerancing Standards” is a 12-page paper that will help organizations decide what path may be the best for them. It includes a summary of the major changes to the ASME Y14.5 standard and insight into what other companies are planning. It also includes my deliberations and recommendations on changing dimensioning standards.

It’s available for $25 on our website.

I am working on a new geometric tolerancing book that explains the use of ISO standards on technical drawings. This comprehensive book can be used for multiple purposes: the topics are organized in a format conducive to learning the topic, plus it contains many features that make it a great reference guide. The book is based on ISO 1101-2004 and companion standards.

This is an exciting project, and I’m anxious to complete the final draft. The book is very close to the expert review stage. The process of having a team of technical experts proofread a new book is an important part of writing a technically sound book. I have learned from previous projects that it always results in a better product.

I have most of the proofreading team in place, but I would like to have three or four additional technical experts who are experienced in ISO GPS. Proofreading requires a commitment of your time. I am estimating the draft will be ready for review by mid to late June, and the technical review must be completed by about 30 days after that.

There is no pay for proofreading, but there are rewards. First, you will enjoy reading and dissecting each section of the book. You may even find some new information on some aspect of the ISO standards. Also, your name will be listed in the credits, and you will receive a free copy of the book when it is published.

If you are experienced in ISO GPS standards and would like to be part of the proofreading team, send me an email describing your expertise level, and I’ll add your name to the list of prospective technical experts for proofreading.

Sincere thanks,

Alex

I’ve had many clients ask me what’s new in the ASME Y14.5-2009 Standard. As you can imagine, a standard that has been 15 years in the making contains numerous changes. There are over 20 new or revised symbols and over 40 new or revised terms. In fact, almost every paragraph of the standard has some revision.

In order to provide a quick reference illustrating many of the standard changes and additions, I’ve created a set of charts comparing the features of ASME Y14.5M-1994 and ASME Y14.5-2009.

The New Features Comparison Chart Set is a comprehensive set of two, 2-sided, 11×17 charts that itemize changes in the standard. It highlights additions, revisions, and modifications to symbols, terms, and modifiers, including changes to the MMC modifier, feature of size and “irregular” feature of size, the new datum translation modifier, and numerous other new features.

Because it provides the 2009 standard references, you can quickly look up additional information as you need to on the job. The charts fits neatly in a 3-ring binder.

The two-chart set is only $12.

We’ve been pretty busy this spring, preparing courses, books, workbooks, and charts to keep pace with the new ASME Y14.5-2009 Standard.

Aside from that focus, we also finished developing our latest web-based training course on engineering drawing requirements. The course contains four lessons that cover:

• The definition and uses of engineering drawings
• Types of engineering drawings
• Appropriate standards and documents specified on engineering drawings
• Basic part definition required on engineering drawings

The web-based course is geared to people who work with and interpret engineering drawings. It’s based on Y14.100-2004 and Y14.24-1999 standards, takes about 4-6 hours to complete and can be purchased for 30-, 60-, or 90-day access. It includes practice problems, quizzes, and a drawing packet containing 12 engineering drawings in printable PDF format.

With many companies undergoing budget cuts, this online workshop is perfect for those who need training but can’t travel to our public workshops. You can read more about the course and the complete list of drawings that are covered at our ETI Learning Center website.

We also have a tutorial that you can view to get a preview of the course. View the tutorial.

By now, many of you have heard that ASME Y14.5-2009 has been released. The new version of the dimensioning and tolerancing standard for GD&T incorporates many significant changes, including:

• New symbols and terms
• Revisions to concepts, symbols, and terms
• Clarification to existing concepts

Many companies are in the midst of cost-reduction programs and are under intense pressure to increase productivity. As a result, the timing of this new standard’s release has caused an unexpected challenge for industry. Changing dimensioning and tolerancing standards is a major effort, and the decision should be made with as much information as possible.

Here at ETI, companies have been requesting information about what is going on in industry relative to dimensioning and tolerancing standards. With that in mind, I have created a short survey to collect statistics regarding companies’ plans for either adopting the new standard or adopting ISO standards.

When the survey is complete, I will share the results with all the survey participants. I will also provide a white paper of my personal insights on the benefits and risks of early adoption. It will discuss points to consider when deciding to adopt the new ASME standard or change to ISO standards.

I hope you will take a few minutes to complete this short, 10-question survey. The individual results will be confidential; only group data will be published.

Best regards,
Alex

I recently co-authored an article with my colleague James R. Roll about the importance of using GD&T for detecting bad design before production. The article, “Avoiding Design Problems With Geometric Dimensioning and Tolerancing,” was published a few weeks ago in Machine Design magazine.

Here’s a short excerpt:

Datum selection is the best place to start when managing variation during the PDP. A robust datum scheme uses datums that best prevent the parts from moving out of position, minimizes the number of items in a tolerance stack, is well controlled within the part (location tolerances and rigid features) and is shared by as many manufacturing processes as possible.

The datum scheme is largely driven by the product-build strategy and system requirements, thus it is important to consider the effect of datum selection early in a PDP (requirements and system design phases). The design-and-build strategy defined at this stage will have the largest effect on product quality with the least cost. Mistakes made at this stage will be expensive to fix at later stages, if they can be corrected at all.

Please read the full article at the magazine’s website here and let me know what you think. I look forward to your feedback.