As Director of Technology and Industry Research for PMPA, Miles brings 38 years of hands-on experience in areas of manufacturing, quality and steelmaking. He helps answer "HOW?","WITH WHAT?" and "REALLY?"
In 2009, while two of the three bankrupt-thinking Detroit firms were using the government to bully their way through bankruptcy, running roughshod on their suppliers and creditors, I wrote a piece about “The New Domestics.”
Here are a few points that I made in that article:
More than 70 percent of the value added in a new car is provided by the suppliers, not the assemblers
More than 300 companies have created jobs in Ohio as a result of the state’s “New Domestic” auto industry
Honda has plants or major operations in Alabama, California, Connecticut, Colorado, Georgia, Indiana, Iowa, Michigan, New Jersey, North Carolina, Ohio, South Carolina, Tennessee and Texas
Mercedes has a plant in Alabama, too
BMW has a plant in South Carolina
Volkswagen has broken ground for an assembly facility in Chattanooga, Tennessee (it’s been making cars since 2011 and employs 2,000 people)
So what is an American car? One made by my friends and neighbors, made from materials and parts purchased locally, one that the first digit of the VIN is a 1, and one that has more than 50 percent “domestic content.”
What is the U.S.’s leading auto exported abroad? Read the surprising answer here.
Postscript: This is not to diminish the role of Canadian manufacturers, nor their vehicle assembly plants. PMPA members in Canada produce high volumes of high technology system parts for the automotive markets—fuel injectors, anti-lock brake parts, fluid power system components and much, much more. But the irony of the whole Ford “wrap ourselves in the flag while we really export your jobs” marketing is the “driver” behind this post.
Chemical manufacturers, importers, distributors and employers are now required to provide a common approach to classifying chemicals and communicating hazard information on labels and safety data sheets. The June 1 deadline was established when OSHA aligned its Hazard Communication Standard in 2012 with the global standard for chemical product labeling.
Chemical manufacturers and importers must provide a label that includes a signal word, pictogram https://www.osha.gov/dsg/hazcom/pictograms/index.html, hazard statement, and precautionary statement for each hazard class and category. Beginning in December, distributors may only ship containers labeled by the chemical manufacturer or importer if the labels meet these requirements. Until then, your shop will likely see containers with old or new pictograms and information.
Vacuum treated (vacuum degassed) steel is used for critical applications that require steel with an exceptionally high degree of structural uniformity, internal soundness, and other characteristics that may be impaired by the effects of uncontrolled amounts of dissolved gases. Vacuum degassing treatments, along with various deoxidation practices, are specified to control the amounts of dissolved gases in the steel. The benefits of vacuum treatment include:
Reduced hydrogen content, which reduces steel’s tendency to “flake” or become “embrittled.”
Reduced oxygen content, which makes it easier for the steel to conform to restrictive microcleanliness requirements.
Improved recovery and uniformity of alloying elements and other additive distribution.
More controlled steel composition.
Higher and more uniform transverse ductility, improved fatigue resistance, and improved high temperature performance.
Can be used to achieve exceptionally low carbon content that are otherwise unobtainable by conventional means.
What are some situations where vacuum treatment is employed?
Large forgings and large cross sections where hydrogen would otherwise remain and contribute to flaking and embrittlement.
Bearings where uniformity throughout the section is important for critical performance.
Inverted delta, human critical safety applications where steel toughness and performance place high demands on the steel’s properties in all directions.
The removal of oxygen by degassing is a challenge for the steelmaker, because this element is extremely reactive: It can exist in the steel in many forms, such as free oxygen; it can dissolve in the melt as a soluble nonmetallic oxide; it can combine with carbon to form gaseous oxides; and it can exist as complex oxides in the accompanying slags and refractories in the process.
While it is best to measure using the parameter specified in the print, there are rules of thumb available that can help clear up the confusion and convert Ra to Rz or Rz to Ra.
The methodology of measurement and what is measured are quite different. This is critical to understand if you will not be paid for your parts because the Ra you measured is not in fact the Rz surface profile that customer specified.
According to an article in Modern Machine Shop written by George Schuetz, director of precision gages at Mahr Federal, “Ra is calculated by an algorithm that measures the average length between the peaks and valleys and the deviation from the mean line on the entire surface within the sampling length. Ra averages all peaks and valleys of the roughness profile and then neutralizes the few outlying points so that the extreme points have no significant impact on the final results.
“Rz is calculated by measuring the vertical distance from the highest peak to the lowest valley within five sampling lengths, then averaging these distances. Rz averages only the five highest peaks and the five deepest valleys—therefore, extremes have a much greater influence on the final value.”
According to doctor blades manufacturer Swedev’s website, “Ra is the arithmetical average value of all absolute distances of the roughness profile from the center line within the measuring length. Rz is the average maximum peak to valley of five consecutive sampling lengths within the measuring length. Ra averages all measurements and does not have any discriminating value in separating rejects from acceptable cylinders.”
And by the way, the definition of Rz has also changed over the years. Which definition of Rz exactly is your customer using? How do you know?
You will find “Conversion Ratios” on the internet provided by well-meaning people. But how useful can these be when the range said to be equivalent goes from 4:1 to 7:1 to 2-:1? 4:1 is equivalent to 20:1? Really? Not in my math class.
Smart shops will avoid using these “approximations in name only” and communicate with their customers to determine the customer’s true need. Gambling on conversion factors that you found on the internet is not professional. It is an example of poor engineering practice, and it fails to serve and protect your customer.
Surface finish measurement procedures, general terminology, definitions of most parameters and filtering information can be found in American Standard ASME B46.1 – 2009, Surface Texture, and in International Standards, ISO 4287 and ISO 4288.
The National Technical Conference (NTC) is one of PMPA’s most valued deliverables. Produced by members for members, this conference shares how-tos across the range of our industry’s challenges—operations, management and quality. Presenters are people that can (and do) do the work. Presenters at the conference include:
Building an Effective Training Program being presented by Shingo Silver Award winning shop experts Dan Vermeesch of Micron Manufacturing Company and Dave Masereau of Boston Centerless.
Gary Griffith (the highest ranked presenter) is back with a great workshop on GD&T.
Diane Thielfoldt will talk more about our millennial workforce.
There are also sessions on troubleshooting, ISO 9001:2015, rapid improvement events, finish issues, shopfloor math, innovating with CAM and CNC, print and part review, just to name a few. This conference is truly packed with a host of opportunities for your team to bring back new ideas and new capabilities to your shop.
The NTC runs from April 19-21 in Columbus, Ohio, with the Precision Machining Technology Show (PMTS) immediately following the conference. (Your registration to the NTC will automatically register you for PMTS.)
Sign up now for the National Technical Conference.
Want more info on programs offered? Click this link to review more than 30 sessions that are packed within these 2 ½ days of training.
Don’t miss your chance to upgrade the skills of your team and the capabilities of your shop.