Most Read Posts in 2014

December 23, 2014

Here are our  ten most read posts this year:

accuracy_vs_precision_220

The Difference Between Accuracy And Precision Measurement In Your Machine Shop

jominy21

Hardness vs. Hardenability-There Is A Difference

Quench crack Sami1stcracked

7 Causes For Quench Cracking Of Steel

manganese_225183515_std1

5 Facts About Manganese in Steel

1211992349-forklift-stans

5 Questions for ForkLift Inspection Compliance

friction weld

7 Advantages of Friction Welding

cold-work-graph

5 Benefits of Cold Work in Steels

grain-size-reticle

5 Engineering Aspects of Austenitic Grain Size

temper-embrittlement

Blue Brittleness, Temper Embrittlement, 400-500 Degree C Embrittlement And More

2-solutions-quadratic

Multiple Solutions, Custom Tooling, And Your Precision Machining Shop

We hope that you find this review of our most popular posts helpful to your work in the upcoming year.


November PMPA Business Trends- A Return To Seasonal Normal

December 22, 2014

 

The PMPA Business Trends Report Sales index for November plummeted 23 points from 132 to 109, a drop of almost 17%. Here are 5 reasons why we are unconcerned by what most would call a panic-worthy drop.

That drop tells us more about October's record than it does about November sales

That drop tells us more about October’s record than it does about November sales

  • The November value of 109 actually “just happens to be” the arithmetic average of the index for the last 4 Novembers.
  • The drop is more  about the record high in October than it is about a low November.
  • Sentiment for Lead Time remains level for the next three months- our shops know their capacity and see it remaining the same.
  • Sentiment for future  Profitability, Employment, and Sales all increased in November despite the drop in actual sales.
  • November and December are typically weak sales months for our industry. January sales will likely be “gangbusters” as our customers return to work after end of year tax inventory and holiday shutdowns.

By the way, the average length of first shift hours scheduled was 43.5 hours, just a half an hour short of 44 hours- which means average shop in our industry was just short of working 10% overtime as a regular schedule- despite that “huge drop” in sales.

The outlook for precision machining is looking strong according to the 87 respondents in our survey and report.

PMPA Business Trends Report for November 2014

 

 


NLRB Action This Week Will Hurt Manufacturing Employees and Employers

December 12, 2014

Washington, D.C. – The Precision Machined Products Association (PMPA) today strongly criticized the release by the National Labor Relations Board (NLRB) of a rule which restricts the rights of employees and drives a wedge between employers and employees.

 

On Friday, December 12, the NLRB released the “Ambush Election” rule, which limits the amount of time employees have to consider whether or not to join a union to as little as 10-14 days, down from an average of 56 days. The new rule, which takes effect April 14, 2015, also requires businesses to supply unions with the phone numbers and email addresses of employees ahead of an election, exposing workers and their families to unwanted calls at all hours. In a legal challenge supported by PMPA, the U.S. District Court for the District of Columbia previously struck down a nearly identical version of the rule.

“While we are disappointed with the NLRB’s actions, we are not surprised,” said Miles Free, co-Interim Executive Director of the PMPA. “This rule continues a disturbing trend by the NLRB to drive a wedge between employers and employees. The current system is already working and employees need time to weigh their options and understand what is at stake,” continued Mr. Free.

Regardless of a company’s size, actions like this sends a ripple effect throughout the manufacturing supply chain. Prior to the courts rejecting the NLRB’s earlier attempt, the U.S. Congress, whether under control of Republicans or Democrats, repeatedly refused to act on this proposal in legislative form.

 

Opponents of the most recent Ambush Election rule are exploring their legal options and expect to take action in the courts in the near future to challenge the NLRB’s authority to take this restrictive action.


Ductility- As Measured By Tensile Testing

December 11, 2014

The ability of a material to deform plastically without fracturing, is called ductility. In the materials usually machined in our shops, ductility is measured by determining the percent of elongation and the percent reduction of area on a specimen during a tensile test.

Our earlier post about Ductility showed how ductility can impact our shops. In this post, we will describe how we can measure ductility and use it to predict behavior  based on values reported on certs and test reports.

The percent elongation and percent reduction of area values shown on our test reports and material certifications from our material suppliers indicate the ductility of the material tested.

In the tensile test, a cylindrical specimen is gripped securely and subjected to  a uniaxial load and elongated until it breaks. At the end of the test, the pieces of the fractured specimen are fitted back together again and the change of length between the two gage marks put on the specimen before testing is determined. The change is then expressed as a percentage of the original gage length.

Fractured specimen fitted back together then measured

Fractured specimen fitted back together then measured

The percent reduction of area is determined by measuring the minimum diameter of the broken test specimen after the two pieces are fitted together and the difference is  expressed as a percentage of the original cross sectional area prior to the test.

 

The  differences in measurements after tensile test are used to calculate the % elongation and % reduction of area

The differences in measurements after tensile test are used to calculate the % elongation and % reduction of area

A minimum of 12% elongation  is recommended for  consistent, trouble free thread rolling applications.

Rolled threads are stronger, so having the ductility to thread roll is important. However, too much ductility makes it difficult to get the chip to separate by cutting.

Low ductility can be problematic for cold deformation manufacturing processes such as thread rolling, cold forming, swaging, staking and crimping.

This is the designer’s compromise: if it is good for cutting, it is probably not very good for rolling.

 

And Vise-Versa

And Vise-Versa

HSC online Graphic of test specimens

Yost made in USA vise photo credit


November ISM Report-Manufacturing Sustains its Strength

December 1, 2014

 

” Economic activity in the manufacturing sector expanded in November for the 18th consecutive month, and the overall economy grew for the 66th consecutive month, say the nation’s supply executives in the latest Manufacturing ISM® Report On Business®.”

Manufacturing sustains expansion in November 2014

Manufacturing sustains expansion in November 2014

” “The November PMI® registered 58.7 percent, a decrease of 0.3 percentage point from October’s reading of 59 percent, indicating continued expansion in manufacturing. This is consistent with a 5.1% annualized rate of change in inflation adjusted GDP.”

This was above expectations  and indicates a sustained expansion of manufacturing.

In other good news for our manufacturing shops – ISM’s Miscellaneous Manufacturing; Fabricated Metal Products;  Electrical Equipment, Appliances & Components; Plastics & Rubber Products; Machinery; Transportation Equipment; and Primary Metals  respondents reported growth in November.

“The New Orders Index registered 66 percent, an increase of 0.2 percentage point from the reading of 65.8 percent in October.  The Employment Index grew for the 17th consecutive month, registering 54.9 percent, a decrease of 0.6 percentage point below the October reading of 55.5 percent.”

These are all positive indicators for manufacturing.

Materials impact in November

Inventories of raw materials registered 51.5 percent, a decrease of 1 percentage point from the October reading of 52.5 percent. The Prices Index registered 44.5 percent, down 9 percentage points from the October reading of 53.5 percent, indicating lower raw materials prices in November relative to October. This is a major change from the strength of the prices index in the recent past.

How this relates to our precision machining shops:

The PMPA Business Trends Index for October increased a whopping 13 points (10.9%) from 119 to 132.  This is the highest value for our index, ever.   While this was an unexpected show of strength for our industry, we did confirm our data and noted that over 40% of respondents reported double digit sales increases for October.

The ISM PMI  indicator’s strength in November leads me to believe that our shops will also report stronger than expected results in our November Business Trends Report.

How is your shop dealing with the unexpected strength in demand for your products?

ISM November Release
Calculated Risk Blog PMI Graph

 


Thanksgiving- A Time to Recalibrate

November 26, 2014

We have many blessings in our lives, the love of family, friends chief among them.

Thanksgiving is a time to share with family and friends.

Thanksgiving is a time to share with family and friends.

Most of us enjoy an unparalleled material well-being, and a lifestyle of modern convenience that is the envy of the world.

Thanksgiving provides us the chance to recognize and thank the engineers, machinists, and entrepreneurs who have designed and built these modern technologies that keep us safe, comfortable, and make our modern lifestyle possible.

Precision machined components enable almost all modern technologies to function safely and efficiently.  It makes me smile to understand where all this behind the scenes technological  “magic” is sourced.

Thanks to the machinists who make them, the engineers that design them, and the investors who tool up their shops to be able to produce them.

Thanksgiving is also about recognizing how our loved ones contribute to our ability to produce our highly engineered components. How they help us keep in mind what “Safety Critical” really means.  How they make sure we have what we need when we arrive on the job. And have a reason to return home, all body parts intact. Now is a great time to recognize the contributions of our loved ones to our success.

I am thankful for the blessings of my family and friends.

I am grateful to live in a time where technology makes my life more about the joy of my family’s company than about battling forces to merely survive. Technology works, thanks to machinists.

In our shops, we have calibration routines to help us assure that our output is to spec and acceptable.

We have calibration routines at work; how do we calibrate our lives at home?

We have calibration routines at work; how do we calibrate our lives at home?

Thanksgiving is a day for us to recalibrate and reflect on the blessings that collectively we share.

Happy Thanksgiving!

Vintage Thanksgiving Dinner photo credit

Calibration photo credit


What Does Ductility Mean?

November 19, 2014

The ability of a material to deform plastically without fracturing, is called ductility. In the materials usually machined in our shops, ductility is measured by determining the percent of elongation and the percent reduction of area on a specimen during a tensile test.


Ductility is often indicated by chip control issues in certain steels, as the chip readily deforms but does not separate from the work piece. This  can result in persistent burrs attached to the work .

Ductility arrives in our shops as indicated by burrs

Ductility arrives in our shops as indicated by burrs

Ductility can also mean  long stringy chips that can form a dreaded “birds nest” engulfing the tool and work piece.

Test text

Birds nest chips present a very real danger to operators. Ductility can hurt!

Long necklace chips are another sign of ductile materials in machining.

long continuous chips resulting from ductile material can be controlled to keep them away from work piece and tool

Long continuous chips resulting from ductile material can be controlled to keep them away from work piece and tool.

Short chips curled into  “sixes and nines” showing a bit of heat discoloration are typical of less ductile materials and dutile materials machined at proper parameters using chip breakers and high pressure coolant delivery.

Note the touch of heat discoloration shown on the chip as well.

Chips that look like sixes or nines showing a bit of heat discoloration are desired for safe practice.

 

In our machining practice we would prefer materials that are “crisp” rather than ductile.

In order to successfully deal with ductile materials, strategies such as chip control features on inserts, wiper style inserts, through tool coolant,  interrupted cuts, chip breakers, and high pressure coolant can be considered.

Dialing in the appropriate feeds, speeds and depth of cut are crucial too.

Birdsnest photo courtesy Garage Journal

All other photos by author.


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