Speaking of Precision

Speaking of Precision is a knowledge preservation and thought leadership blog covering the precision machining industry, its materials and services. With over 36 years of hands on experience in steelmaking, manufacturing, quality, and management, Miles Free (Milo) Director of Industry Research and Technology at PMPA helps answer "How?" "With what?" and occasionally "Really?"

What About the Chips?

Posted August 06, 2019 12:00 PM by Milo
Pathfinder Tags: chips machining manufacturing

Our customers are interested in what is left after we remove the chips. But it is up to us as operators and engineers to understand that there are differences in our chips based on process, material and tooling factors- and what those differences mean.

The infamous “Bird’s Nest Chip”

Process Differences

Turning can result in a long continuous chip, while sawing or milling processes result in shorter chips because of the interrupted nature of the cut. Drilling can result in the chips being recut depending on how the tool is fed and the nature of it’s spiral and means of chip evacuation.

Different materials can drive differences in the chips as well. I’m a steel guy, so my comments are based on that experience, but similar differences will be found in other materials, just based on different factors than Carbon.

Material Differences

Plain Carbon, Low Carbon Steels (C1008, C1010) tend to generate a more Continuous, Soft Chip. Plain Carbon, Medium Carbon Steels (C1030, C1045) can give a Continuous, Semi-Soft Chip. Plain Carbon, High Carbon Steels yield a Continuous, Hard Chip. Adding alloys can result in a Continuous, Semi-Hard Chip at lower carbon contents (4120) while higher carbon alloy steels can result in a Continuous, Tough Chip (4150) Very High Carbon Alloy steels (52100) give a chip that is both Continuous and Springy.

Having said that, I do not mean to say that all of these steels will result in long stringy chips- it is just that compared to Resulfurized Steels, such as 1117, 1144, 1215, or 12L14, the chips are far less likely to fracture into nice short pieces- often called “6’s or 9’s” or “C’s.” These chips can be described as Broken Semi-Soft (1117) or Broken Semi-Hard (1144) or Well-Broken Semi Hard (12L14, 1215)

Process Parameters

Finally, having the speed, feed, depth of cut, and angles on the tools is critical if we are to optimize material removal, minimize chip volume, and keep our process stable and maximize our uptime. Chip control features can also play an important role. ISO 3685 characterizes chips into 8 types- Ribbon, Tubular, Spiral, Washer-type Helical, Conical Helical, Arc, Elemental , and Needle chips. These can then be further described by length (short, long, or snarled).

Source ISO 3685

The ISO 3685 standard is a bit pricey, but it will help you to better understand what is going on in your turning process.

Of course you can look at the part, but to learn about your processes may I suggest that you take a really good look at the chips?


Editor's note: CR4 would like to thank Milo for sharing his blog, which can also be read here.

2 comments; last comment on 08/08/2019
View comments

Quality Quote

Posted October 23, 2018 11:00 AM by Milo
Pathfinder Tags: machining quote standards

No spec, no quality. Know Spec, know quality.

Quality means compliance with all terms of the specification.

Know the specification!


Editor's note: CR4 would like to thank Milo for sharing his blog, which can also be read here.


Why Precision Machining Matters - Lothar Horn

Posted October 16, 2018 1:00 PM by Milo
Pathfinder Tags: machining manufacturing

I am always pleased when I encounter a quote that neatly communicates an Idea that I firmly believe, but is expressed more clearly than I could.

Imagine my delight when I received a placard containing one of my favorite industry quotes today!

So happy to get this visual reminder of the importance of precision machining, and the tools that we use!

Read the Card!”

“Read the card!”

“What’s it say?

NO CAR RUNS, NO AIRCRAFT FLIES AND NO HIP REPLACEMENT IS FITTED BY A DOCTOR WITHOUT PRECISION TOOLS HAVING PREVIOUSLY BEEN IN USE.”

As precision machinist’s, we’re the people that make things.

Things that make a difference in everyone’s quality of life.

And who is is it that makes the tools that help us make that difference?

Why, precision toolmakers, of course.

A big thank you to Horn USA for sharing the placard with my favorite quote.

See you all at IMTS!


Editor's note: CR4 would like to thank Milo for sharing his blog, which can also be read here.

1 comments; last comment on 10/19/2018
View comments

Beryllium Standard Final Rule: Do You Machine Beryllium?

Posted August 07, 2018 1:17 PM by Milo

The 2017 final rule established new permissible exposure limits.

It also included provisions to protect employees from exposure to Beryllium, such as

  • requirements for exposure assessment,
  • methods for controlling exposure,
  • respiratory protection,
  • personal protective clothing and equipment,
  • housekeeping,
  • medical surveillance,
  • hazard communication,
  • recordkeeping

Do you machine Beryllium in your shop?

Have you evaluated your compliance to the above 8 points of regulatory concern?

Do you know the key regulatory enforcement and compliance dates?

Beryllium Copper is not only used in electrical applications!

If your shop machines any of the following Beryllium Copper grades, it does apply to you:

Beryllium Coppers C17000, C17200, C17300, C17410, C17500, C17510

The rule applies to occupational exposure to Beryllium in all forms, compounds, and mixtures in
general industry, construction, and shipyards.

  • Employers that are covered under the rule must use engineering and work practice controls to
    keep exposures at or below the PELs.
  • Engineering controls include using process isolation, ventilated enclosures, or local
    exhaust ventilation to keep beryllium from being dispersed throughout a work area.
  • Examples of work practices to control beryllium exposures include keeping surfaces
    clean by using a HEPA-filtered vacuum or by wetting down dust before sweeping it up.
  • If engineering and work practice controls cannot keep exposures at or below the PEL,
    employers must provide respiratory protection to affected employees.

PMPA is providing members with sensemaking regarding this final rule, compliance dates and strategies, and helpful links to better understand their responsibilities.

PMPA Beryllium Final Rule Members Only

Photo of VR38 Nissan GTR Beryllium Copper Valve Seats courtesy of Fast Forward Race Engines on Facebook

Not a PMPA member? Contact Matthew Hooper to learn more mhooper@pmpa.org.


Editor's note: CR4 would like to thank Milo for sharing his blog, which can also be read here.

1 comments; last comment on 08/09/2018
View comments

7 Industry Trends to Think About, New Technology Isn’t One of Them

Posted December 26, 2017 10:30 AM by Milo
Pathfinder Tags: machining manufacturing trends

You may be surprised that Technology as a stand alone item is not one of them.

Our future is not about shinier flying saucers.

We will master and implement whatever technologies are developed.

But our future is being impacted by these 7 items today:

  1. Loss of experienced workers taking tribal and craftsman knowledge out of our shops.
  2. Lower average wages as experienced workers with seniority leave and younger workers start at trainee wages, making it difficult to attract talent with facts about “increasing wages”- even though they are.
  3. Training growing in percent of spend as many shops are unable to purchase new technology to quote new work because they do not have trained workforce.
  4. More and more jobs being quoted out of more challenging, non free machining materials;
  5. A bit of relief from new regulations, but more uncertainty as Washington turns to trade issues which can impact availability and cost of imported materials, and tooling, as well as impact the exports of finished goods that contain our parts.
  6. Increasing demands for certification of production to a wide variety of customer demanded requirements regardless of legal obligations- Conflict Minerals, REACH, RoHS, Animal- Free; Ca. Prop 65. Etc.
  7. Possibility of an “Association Healthcare Insurance solution” in 2019 or beyond.

What do you see as the trends shaping our company and industry future?

Please don’t say technology- as Humans, we’ve been successfully implementing new technologies for quite some time.

Flying cars

Todd Rundgren Future

Fire


Editor's note: CR4 would like to thank Milo for sharing his blog, which can also be read here.

27 comments; last comment on 05/17/2018
View comments


Previous in Blog: Craft Advice for Machinists: How Good Can You Get?  
Show all Blog Entries in this Blog

Advertisement