Top Ten OSHA Violations in 2017

October 4, 2017

Deputy Director  of OSHA’s Directorate of Enforcement Programs Patrick Kapust presented the agency’s preliminary list at the National Safety Congress and Expo on September 26.

Powered Industrial trucks 1910.178 makes the TOP TEN again in 2017

Here are the Top Ten, along with the number of citations.

  1. Fall Protection – General Requirements (1926.501) – 6,072
  2. Hazard Communication (1910.1200) – 4,176
  3. Scaffolding (1926.451) – 3,288
  4. Respirator Protection (1910.134) – 3,097
  5. Lockout/Tagout (1910.147) – 2,877
  6. Ladders (1926.1053) – 2,241
  7. Powered Industrial Trucks (1910.178) – 2,162
  8. Machine Guarding (1910.212) – 1,933
  9. Fall Protection – Training Requirements (1926.503) – 1,523
  10. Electrical – Wiring Methods (1910.305) – 1,405

If you are just now reviewing your OSHA training  performance, these standards would be a great place to start.

The  items numbered 1910 are General Industry, those numbered 1926 are Construction.

Photo courtesy Staffing Talk

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Technology- Profit Differentiator or Limiter?

September 5, 2017

I have had some interesting conversations with a couple of shop owners after they read our article Technology or People in the July issue of Production Machining.

The point that I had hoped to convey was that while the contributions of technology to our shops’ bottom lines is undeniable, it is up to us to get our people in position to take maximum advantage of the technology- to lead the technology.

Technology As Enabler

One correspondent pointed out that they purchased technology so that they could still get production with the available manpower in their area. They thought that getting people who could use the technology that they had was chore enough. They were buying technology with canned cycles so that they could produce with out a lot of engineering and programming, which was not a strength of theirs based on their workforce.

Technology As Equalizer

Another person called to discuss the article and said that to them, they thought that technology was in fact a “great equalizer” or “homogenizer.” That shops with the same technologies would likely quote similar parts to similar times and costs based on using the technology in similar ways based on how it was equipped from the factory. So they saw technology not as a way to differentiate  shops, as much as a way for multiple shops to get to a common and competitive level of performance.

Technology as Empowerment

The third caller raised the point that I had tried to make, but in much richer detail. “If you use the machine just out of the box, you’re no different from anyone else. If you use the machine’s built in roughing cycles,  for example, you’ll get the exact same result as everyone else with that same machine. The profits are made when you go out past the “built in” capability and create greater value by customizing your process.  On a complicated part, using the machine “normally” might require you to use 12 tools, and require a very expensive machine because of the relationship of certain features to each other. But what if I build several of those interdependent features into a special tool, whether OD form, or ID step drill, for example? Now I don’t need so many consecutive tool’s stacked up to do the cutting and adding up time for each part. Because the features are built into the tool, I don’t need so much precision out of my machine. And now I don’t need all of those expensive stations… ”

They had quite a bit more to say about how the canned cycles are conservative and wasteful and in some cases a compromise that  might not be best for the particular job. But when I thought about what he had said, it raised a question in my mind- “Since we don’t need so many tools and so much precision because of the “novel way” that was determined that would work- “Doesn’t that mean we don’t need that original expensive high tech machine tool?”

Not So Fast, Vigo!

The third caller shared how they were able to make parts using a sub $100,000 mill in their shop- while their Customer could not get the parts correct on their million dollar plus technology.

Was he saying that the little guy and the cheap equipment will always beat the big guy and their expensive technology? Not at all.

What he was saying is that it is up to all of us to assure that our people and our technology are operating at their highest and best use. Not just their nameplate or nominal capacity.

He was saying that technology is the tool that can best help us achieve our vision and fully realize our abilities. Technology is the best means available to us to deliver the best that we can think of. It is our thinking therefore, that leads our technology.

Final Questions

What is the purpose of technology in our shops?

Is it to substitute for knowledgeable people and still get acceptable parts to ship?

Is it to ensure that our shops are competitive in the market?

Is technology merely a means to an end, and best driven by deliberate intention to give the engineer the ability to make the parts the best way that they know how? Without the need for an unnecessary investment?

Or is technology the tool that empowers our people to deliver the best that that they can imagine?

What Is The Purpose of Technology In YOUR Shop?

Thanks to the folks that gave me a shout to discuss the article. We learn so much from our conversations.


Thank You to My Readers

April 12, 2017

Actually, a million thank yous! Thanks to readers like you, SPEAKINGOFPRECISIONBLOG has over 1,000,000 views.

1,000,000 views!

Our first post  was from June 30, 2009 and remains as relevant to day as it did then: 5 Reasons to choose a Career in Precision Machining

We’ve come quite a way since that very first post!

What do you like? 

Our post on The Difference Between Accuracy and Precision Measurement in Your Machine Shop is our most popular with 44,445 views.

Hardness vs. Hardenability- There is a Difference is our second most popular post at 35,780 views.

5 Facts About Manganese in Steel, 7 Causes for Quench Cracking of Steel, and Why Manufacturing is the Right Career Choice- DATA! all came in between 21,000 and 30,000 views each.

Average number of times a post gets seen on PMPASPEAKINGOFPRECISIONBLOG: 1048 times.

1,000,000 is an aspirational number. How many of us get to measure anything that we do in quantities of millions?  (Actually, all of our shops do, they call it “normal production!”)

But as an individual, as someone sharing knowledge and experience- 1,000,000 views;  1,000,000 shares of information; 1,000,000 human to human connections- that is an unexpected and very satisfying validation.

Thank you for spending a small part of your day with me here at my blog.

Together, we’ll continue to make sense of the the issues that make a difference to all of us in North American Manufacturing.

Especially Precision Machining.

1,000,000 views!

Do I believe in the power of social media to help us connect and share?

You bet I do! 1,000,000 times YES!

Tooting Own Horn  photo credit.


Decarburization and Your Precision Machine Shop

March 17, 2017

Decarburization on surface layers can affect heat treatment and hardness attained on parts. Decarburization also provides evidence of where in a process a defect or imperfection occurred.

Most defects  in steel workpieces encountered in our precision machine shops are longitudinal in nature. While their presence alone is enough to concern us, for the purposes of corrective action, it becomes important to identify where in the process the longitudinal imperfection first occurred. Visual examination alone is not enough to confirm the source. Did it occur prior to rolling? During rolling? After rolling? Understanding decarburization and how it presents in a sample can help us to identify where and when  in the process the imperfection first occurred.

The question that we want to answer as part of our investigation is usually “When in the process did the defect first occur?” Looking at decarburization and any subscale present can help us answer that question with authority.

What is Decarburization?

The light area (ferrite) surrounding the dark intrusion is decarburization. note the lack of pearlite in this decarburized (lighter) zone. There is no evidence of scale, indicating that this defect was created during, rather than prior to rolling.

“Decarburization is the loss of carbon from a surface layer of a carbon containing alloy  due to reaction with one or more chemical substances in a medium that contacts the surface.”Metals Handbook Desk Edition

The carbon and alloy steels that we machine contain carbon. In the photo above, the carbon is contained in the pearlite (darker) grains. The white grains are ferrite. In an etched sample, decarburization surrounding a defect is identified as a layer of ferrite with very little, or none of the darker  pearlitic structure typically seen in the balance of the material. The black intrusion in the photo above is the mount material that has filled in the crevice of the seam defect.

What is Subscale?

The grey material adjacent to defect within the white decarburized area is subscale. This subscale is evidence that the crack was present on the bloom prior to reheat for rolling

Subscale is a reaction product of Oxygen from the atmosphere with various alloying elements as a result of time at high temperatures. The presence or absence of the subscale is the indicator that helps us to pinpoint the origin of the defect. For a subscale to be present,  the time at temperature must be sufficient for oxygen to diffuse  and react with the material within the defect. According to Felice and Repp, 2250 degrees F and fifteen minutes  is necessary to develop an identifiable subscale. Lower temperatures would require longer times. Typically rolling mill reheat cycles offer plenty of time to develop a subscale in a prior existing defect. However, for defects that are created during rolling, the limited time at temperature and the decreasing temperatures on cooling make formation of subscales unlikely.

Reading Decarb and Subscale to Understand the Defect

Decarburization is time and temperature dependent. This means that its relative depth and severity are clues as to time at temperature, though interpretation requires experience and understanding of the differences in appearance from grade to grade based on Carbon content.

Symmetrical Decarburization

If the decarburization is symmetrical this is an indication that the defect was present in billet or bloom prior to reheat and rolling. oxygen in the high temperature atmosphere of the reheat furnace depletes the carbon equally from both sides of the pre-existing defect.

Asymmetrical Decarburization

Decarburization that is obviously asymmetrical indicates that the defect is mechanical in nature and was induced some time  during the hot rolling process.

Ferrite Fingers

Unetched specimen of seam (top). Etched specimen showing “ferrite finger.” (Bottom)

Ferrite fingers are a surface quality problem that is associated with longitudinal bar defects. During reheat, a defect in the bllom or billet is exposed to high temperature atmosphere, forming decarburization and subscale  around the defect. Rolling partially closes or “welds shut” the crack. However, a trail of of subscale is entrained in a  formation of almost pure ferrite which has been depleted of pearlite, carbon and alloy by the reaction at elevated temperature.   This trapped scale remains a potential oxygen source, driving further internal oxidation and decarburization if temperatures remain high.

Continuous improvement requires  taking root cause corrective action. Obviously identifying the root cause is critical. When we encounter longitudinal linear defects in our steel products, using a micro to characterize the nature of the decarburization and presence or absence of sub scale or ferrite fingers are important evidence as to when, where, and how in the process the defect originated.

 

 

 


Stress Cracks in Steel Bar Products.

March 14, 2017

“Stress cracks are defined as transverse or near transverse open crevices created when concentration of residual stresses exceed the local yield strength at the temperature of crack formation. These stresses can be mechanically induced or can be attributable to extreme temperature differences and /or phase transformations. They can originate at almost any point in the manufacture of the steel.”AISI Manual Detection, Classification, and Elimination of Rod and Bar Surface Defects

Stress cracks are often found visually  at locations that experience bending or straightening. They are also referred to as “Cross Cracks” or “Transverse Cracks.” Originally they were identified in mill billet and bloom products, prior to rolling.

Micro examination can help determine crack origin by noting:

  • Orientation
  • Intergranular nature
  • Presence of scale
  • Presence of subscale

Additional microstructural characteristics can reveal the thermal history of heating and cooling at the crack location.

This photo shows stress cracks on a conditioned billet.

Causes and Corrective Action

  • Excessive load during straightening can exceed the local yield strength of the material causing it to crack; reduce load applied by machine, or consider tempering or stress relieving material prior to straightening or further cold work.
  • Cooling too quickly can also induce stress cracks. Critical cooling rates are highly dependent on steel chemistry. Crack sensitive chemistries (Medium carbon and high carbon steels; also medium and high carbon steels with straight chromium or straight manganese additions.) These steels should be slowly cooled through transformation temperatures to minimize the occurrence.
  • Design faults such as
    • Heavy sections adjacent to light sections and sharp corners 
    • Failure to fillet sharp corners
    • Use of fillets rather than tapers
    • Undercuts
    • Overloading the material during fabrication, processing, or application.

Detection of stress cracks  is problematic as their transverse orientation makes them difficult to detect on equipment set up to detect longitudinal defects.

Final caveat: The term stress crack is arbitrarily defined based on industrial usage in the market. It does not necessarily imply anything about the specific metallurgical nature of the crack, I know that a number of people use the term “stress crack” to describe longitudinal cracks on steel bar products as well, which the AISI calls “Strain Cracks.”

 

 


EU Commission- RoHS Exemptions Delayed Again

January 24, 2017

The current exemptions for Lead in work piece materials for our shops will remain in effect and will not expire until the EU Commission completes the current ongoing review of the applications.

They can fly the flags, but getting regulatory decisions on time is not something the EU commission does very well.

They can run the flags up the flagpoles on schedule, but getting regulatory decisions on time is not something the EU Commission does very well.

According to Electronics Industry Portal I-Connect007,  the EU is unlikely to publish  the RoHS exemptions any time soon. Apparently the EU Commission only got around to reviewing the requests last month.  December 15, 2016. December 2016!

And they are only now in the process of preparing draft legislation to be sent to the member states for consideration later this year.

Later this year!

Bottom Line for your precision machining shop and your customers:

  • A decision on the RoHS exemptions of interest to the precision machining industry is unlikely to be made until Fall of 2017.
  • The current exemptions for Lead as an alloying element in steel, Lead as an alloying element in aluminum, Lead as an alloying element in copper will remain in effect and will not expire until the EU Commission completes the current ongoing review of the applications.

Here’s the full statement from I-Connect007

“The EU Commission and Member States continue to meet to discuss the disposition of RoHS exemption renewal requests submitted by industry in January 2015.  During their December 15, 2016 meeting in Brussels, the experts reviewed requests on: Lead as an alloying element in steel (Annex III exemption 6a); Lead as an alloying element in aluminum (Annex III exemption 6b); Lead as an alloying element in copper (Annex III exemption 6c); Lead in high melting temperature type solders (Annex III exemption 7a); Lead in a glass or ceramic other than dielectric ceramic in capacitors (Annex III exemption 7c-I), jointly with exemption request 2015-1; Lead as activator in the fluorescent powder (Annex III exemption 18b), jointly with exemption request 2015-3; Lead in solders for the soldering to machined through hole discoidal and planar array ceramic multilayer capacitors (Annex III exemption 24); and Lead in cermet-based trimmer potentiometer elements (Annex III exemption 34).

“The Commission is currently working on preparing the draft legislative proposals for these and other exemptions) which will be sent to Member States for written consultation.  The drafts will likely be published in the spring; final legislative acts could be published in the Official Journal of the EU (OJEU) in the fall at the earliest. Under the EU RoHS2, all existing exemptions were set to expire by July 21, 2016. However, all exemptions for which industry submitted a renewal application will not expire until the EU Commission completes the current ongoing review of the applications.”

I-Connect007

(PS. Interesting footnote, I searched for an image of the European Union Commission and found the one above-on a blog about the EU Commissions delay to decide on a VISA issue– last April. Not an isolated case of Bureaucratic delay!)

Photo credit: Pulse Blog


RoHS Exemptions for Machining Industry- PMPA Members Know

January 12, 2017

The EU decision on the  RoHS 2011 recast appeals for exemptions for leaded materials for machining is almost a year late- the decisions were due  from the commission January 21, 2016.

January 21, 2016!

rohs-word-cloud

PMPA has reviewed the findings of the study group assigned to review and report on the appeals regarding Lead for machining purposes in Steels, Aluminum, and Copper alloys.

If you are a PMPA member, you can get our summary  providing the latest status of the RoHS exemptions that affect our shops. The EU is almost a year late with their decision on the exemption appeals for leaded materials for machining under the latest (2011) RoHS recast.

PMPA has posted a summary of the consultants’ findings  and their potential impacts on our machining companies for our members information on the PMPA website here.

We have really been challenged by the EU to stay up to date on these exemptions, being almost a year late with the decision certainly keeps the uncertainty high for manufacturers.

I wonder if the European Commission is as  lenient with the deadlines on the regulated communities as they are for their own?

If you are a PMPA member, you can get the latest Status of the RoHS exemptions that affect our shops here : January 2017 RoHS Exemption Summary Report

If you are not a PMPA member, where do you go to stay up to date on regulatory issues that affect your business?