SPECS

Recently, I have encountered some customers who are getting drawings from their customers calling out for material specifications that they don't recognize.  Additionally, I'm finding some customers who typically know the material they usually buy being stumped by dual Specs.  Such as C93200 is Bearing Bronze but but it's also referred to as SAE 660.  Same material  - just 2 different organizations (Copper Development Association - CDA & Society of Automative Engineers - SAE) calling out for the same material.

Well I came across one of my Cross-Reference guides and thought I'd share.  This is by no means a comprehensive list but it's something for some of the common 800 & 900 series alloys.  It lists the UNS, SAE, Alloy description & typical material applications for the following:

Does SAE 841 have a Heat #?

As most of you know, for some time I was in charge of processing and distributing the Material Test Reports (MTR) here at Atlas Bronze. When I first took on the job I was a bit apprehensive.  The importance of the job and the accuracy of the documents was drilled into my head.  After all, I had heard the stories about those people who went to jail for falsifying Certs (see my post , Who knew you could go to jail! ). 

But, since I have no intention of falsifying any documents in my life... I'm safe. There is much to say about Material Test Reports...(and by no means am I an expert). But I did see a common thread of confusion surrounding one type of material - SAE 841, Sintered Bronze. 

Here's the story....

Recently, I had a customer who purchased some SAE 841 Sintered Bronze material from us and requested Certs with this material.  Happily I sent over the Certs and then she came back to me, puzzled, asking...."On your paperwork, do you have anything that indicates the lot #?".  I then replied with my standard reply.  After I did this I decided....I must post this on the blog, I get this question so often with Sintered products, hopefully it will help.

MATERIAL: SAE 841, Sintered Bronze

QUESTION: "On your paperwork (Certs), do you have anything that indicates the lot #?"

ANSWER: Unlike other bronze materials, Powdered Metal (841 Sintered Bronze), is not melted nor heat traceable, so therefore there will be not be a LOT# or HEAT#      

             

Powder metallurgy is the process of blending fine powdered materials, pressing them into a desired shape (compacting), and then heating the compressed material in a controlled atmosphere to bond the material (sintering). The powder metallurgy process generally consists of five steps: 

(1) Blending - The part-specific powder is created by mixing the correct amounts of metals and lubricants to produce the physical and mechanical properties of the finished product.

(2) Molding - the powder is compacted into the desired shape using compressive forces. The part shape is created by compressing the correct blend of materials inside of the part-specific tools.

(3) Sintering - Through the application of heat, sintering permanently bonds the individual metal particles that have been compacted together through the molding stage.  This process is instrumental in providing the majority of the mechanical properties of the final product.

(4) Sizing - Sizing, sometimes referred to as "coining," is the final pressing of the fully sintered part.

(5) Oil Impregnation - Under vacuum, customer-specific oil products are impregnated into the remaining porosity of the completed part.

So looking at the five steps you can see just in Step 1 alone that maintaining a Heat / Lot # is not possible.   The metal is never melted. 

(PS:  I got your feedback that some of you were unable to leave a comment in the Comments section.  It is now fixed, so feel free to add your thoughts.)

   

Are Certs REALLY that important?

Tired of your customer asking for a Cert?  How do you feel about buying a new document storage program to handle the 100,000+ Certs that you've accumulated for basically no reason at all?

I was recently handed the Spring edition of EDM Today.  Much to my delight, I found a very refreshing article (on page 22) under the Roger's Rant section, entitled "Certs and Self-Audits, The Triumph of Symbolism over Substance".  I enjoyed the article so much that I had to contact the author, Roger Kern, to see if I could post it for all you to enjoy.  Let me say that one of my early functions here at Atlas was to prepare the Certifications for our customer's.  So I am a tad bit biased in my assessment as to whether or not Certs are necessary. 

Without further adieu (compliments Roger's Rant @ EDM Today)

Certs and Self-Audits

The Triumph of Symbolism over Substance

In what may be a welcome respite for some readers, the Spring Rant redirects its focus from government excess to a disturbing trend that directly affects our industry.

One of my roles as a consultant is to serve as Quality Manager for one of our industry’s EDM supply companies. As more US industrial companies have adopted ISO 9000, AS 9000, NADCAP, and similar quality disciplines, I have seen an unmitigated proliferation of frivolous customer requests for Certs and Self-Audits.

Certs

In the “good old days”, customers would reasonably request certs for:

• Chemical composition of materials
• Special processes such as heat treating, welding, coating, or plating
• Non-destructive testing
• Inspection of critical dimensions

Requests for certifications such as those listed above are proper and necessary for aerospace, medical, and other critical applications.

However, with the advent of ISO and the like, many customers now routinely request certs for everything including toilet paper. A typical scenario goes something like this:

Customer “A” calls in an order to an inside sales person for a dielectric filter for a wire machine and says “Oh, by the way I’ll need a cert for that.” At this point I get involved. I first need to inform the customer that I can’t issue certs for telephone orders unaccompanied by written documentation of the order since it is impossible to certify anything that that is dependent on oral communications. If and when the documentation arrives, it usually contains the generic boilerplate “Certs Required”. This prompts another call to the customer asking what it is they want me to certify. The answer is invariably: “I don’t know and I don’t care, just make certain that a cert accompanies the shipment.

In response to the above scenario, I have developed what I call the “B.S.” cert. Basically the cert consists of a unique Certification Number, my client’s name, the customer’s name and address, the customer’s Purchase Order Number, my clients Packing Slip Number, and some boilerplate language that says that my client shipped them the item(s) stated on the order and that the items shipped meet industry standards.

My problem with this is that besides being a waste of time and paper, this worthless cert is then perfunctorily stapled to the packing slip by the customer’s receiving department without anyone even looking at it. The request and response are a sham. If the customer can’t take my client’s word that the packing slip accurately reflects the contents of the shipment, then why would they rely on a cert that basically attests that the packing slip is correct?

A good example of the “trust thing” is an experience I had when I owned my own shop and EDM supply company. A very large automotive customer issued an edict that we had to supply certification of billet traceability of all graphite rounds that we sold to them. Many small graphite rounds are made from cut-offs left over from making rectangles out of billets or rounds out of rectangles. No one in the industry can or will provide traceability to billet in small rounds due to the onerous costs such traceability would entail. I checked directly with the graphite manufacturer, and even if I bought the rounds directly from them they could not provide traceability. I communicated this to the customer and assured them that the rounds I sold were genuine and we would certify that fact, but this was not acceptable. I also offered to provide physical properties analysis certs on the shipped rods at an additional charge, but of course an increase in cost was not acceptable either. I later learned that they placed the business with a competitor who guaranteed billet traceability, which is a bald-faced lie. Yet, the customer was fat, dumb, and happy.

Another example of Cert Insanity is a client’s customer that has facilities in Mexico. They require a NAFTA cert in order to import the goods from the USA into Mexico duty-free under NAFTA. Under NAFTA (North American Free Trade Agreement) goods sold amongst the NAFTA member countries consisting of the USA, Canada, and Mexico cross their borders duty-free as long as the products were made in those countries. In this particular instance, the products in question were made in Korea and not eligible for the NAFTA duty exemption. I notified the customer of the situation and was informed that they still needed me to fill out the cert, specifying the goods were made in Korea even though they were ineligible. It states right on the form that submitting the form for ineligible products is a crime and subject to Federal prosecution. I presume they bought the products from someone else who was willing to comply. 
 

Self-Audits

Along with the proliferation of B.S. cert requests has come a corresponding increase in requests for Self-Audits.

Again, in the “good old days”, if a customer wanted to audit your company, they would send an auditor to your facility and conduct an on-site audit. When I owned my own shop, we would dread these nit-picking and time consuming visits by auditors, but we invariably benefitted from the audit findings and improved our practices as a result of the audit. When the auditor left our facility, he was reasonably assured that what was documented in our quality manual was actually practiced on the shop floor.

One of those audits resulted in a finding that our inspectors should have annual vision exams. It was a simple, no-brainer thing that we had just overlooked, and we welcomed the suggestion.

Today, in many cases, the on-site audit has been replaced with the self-audit – presumably to reduce costs. The self-audit is a multipage document containing a series of multiple choice questions on all aspects of a company’s quality practices. Usually, each question can be answered with “Yes”, “No”, or “N/A”. At the end of the survey is usually a stern warning that any negative answers will likely result in the suspension of the business relationship. That certainly makes it tempting to answer all “Yes”!

Needless-to-say, I always complete these surveys truthfully, in some cases answering “No”. In the last ten years I have completed hundreds of these surveys and have never received any follow-up correspondence or visit. Why? Because no one bothers to look at the returned survey. Some clerk makes a check mark on their ISO form and stuffs the survey in a drawer. If customers really cared about my clients’ quality, they’d come and verify it. In fact, in years past, quality system guidelines mandated on-site visits. Unfortunately, for many companies what really matters is the paper trail and not the actual quality.

If the USA is to be competitive with other nations, we need to do a lot better than just shuffle useless paper around in place of real efforts to assure actual quality improvement.

Roger

Aluminum Bronze Factoids

Aluminum Bronzes are a family of copper-based alloys offering a combination of mechanical and chemical properties unmatched by any other alloy series.  This feature makes the Aluminum Bronze the first choice for demanding applications.  No...I'm not on an Aluminum Bronze Campaign kick BUT I love to learn about an alloy family that outshines the rest.  Well at least in some areas!

So what are the attributes that make Alumimum Bronzes so hot and in demand? Check these out:

Excellent Strength - in fact it is similar to that of low alloy steels. 

factoid:  Several common groupings of low-alloy steels, beginning with HY 80, HY 90, and HY 100 steels, are used for building ship hulls, submarines, bridges, and off-highway vehicles. These low-alloy steels contain nickel, molybdenum, and chromium, which add to the material's weldability, notch toughness, and yield strength. When welding these low-alloys steels, preheat and postheat treatments typically are not required.

Excellent Corrosion Resistance - especially in seawater and similar environments, where the alloys often outperform many stainless steels. Aluminum bronzes can be used in environments that are far more aggressive than are tolerated by most other metals.  Like many copper alloys, aluminum bronzes also resist biofouling in both fresh and saline waters.  Aluminum Bronze alloys may be considered for service with a wide variety of chemicals, particularly where is a combination of stress and erosion, but selection must take account of the anticipated temperature & other services conditions.  Here is a sample of some chemicals:  acetic acid, ammonia (dry), Brine, Bromine (dry), Chlorine (dry), Nitrogen, Sodium Carbonate, Phosphate and much more.

factoid:  Stainless steels are known for there Corrosion Resistance properties.  However stainless steel can be contaminated throughout the fabrication process and wind up being highly corrosive.  Such as: iron dust landing on the stainless steel, water stains from resting water, scratches from carbon steel forklifts or carbon steel racks, gouges from improper handling, embedded iron in machine tooling used on carbon steel and not properly cleaned.  Also welding stainless steels can be tricky.  Mistakes in the welding process will result in a weld that is not as corrosion resistant as the base material.

Favorable High Temperature Properties - for short term or long term usage

Good resistance to Fatigue - ensuring a long service life.

factoid:  Aluminum Bronzes happen to possess exceptional...yes, I said exceptional...resitance to fatigue.  (Insert Sarcasm - "Gee, I wish I had an exceptional resistance to fatigue!") This is one of the most common causes of deterioration in marine engineering equipment.  This property is why this material is most suitable for use as propellors and in pump applications. 

Good resistance to Creep - making the alloys useful at elevated temperatures.

Oxidation Resistance - for exposure at elevated temperatures and in oxidizing environments. 

Ease of Casting & Fabrication - when compared to materials used for similar purposes.

High Hardness & Wear Resistance - provides excellent bearing properties in arduous applications.

factoid:  Aluminum Bronzes often provide excellent service in both cast & wrought forms.  A the high end of the wear - and - abrasion - resistance spectrum are special aluminum bronze alloys containing up to 14% alumimum, whose applications include dies for deep drawing and molds for die casting, casting of glass bottles and pressing of vinyl records. 

Ductility - which, like that for all copper alloys, is not diminised at low temperatures

Good Weldability - making fabrication economical

Readily Machined - when compared with other high-duty alloys

 factoid:  Here are some charts for machining purposes....

 - Cutting tool Geometry for Machining Aluminum Bronzes

- Drill Geometry for Aluminum Bronzes

- Reaming Geometries for Aluminum Bronzes

- Recommeded Tap Geometry for Aluminum Bronzes

- Recommeded Milling Cutter Geometries for Alumnum Bronze

Low Magnetic susceptibility - useful for many special applications

Ready availability - in cast or wrought forms

 factoid:  This of course is the most helpful part of dealing with Aluminum Bronzes.  The ability to have a product right off the shelf, cut and shipped within a day or so it extremely helpful.  Atlas Bronze has a wide variety of stocked material....you can visit to see what we've got, http://www.atlasbronze.com/copper_alloys_product_sheet.html.

 

BLANK!

BLANK!   It is the age old problem.  Well maybe not for everyone.  But certainly for machinists.  Typically,  a machine shop does not know about the availability of a "blank" and will wind up buying a more expensive piece of bar stock instead. 

So, here is the scenario....Machine Shop X gets a print from their customer to make a short run of a part that is made from Sintered Bronze. Usually Machine Shop X will just go out and buy a piece of Sintered Bronze bar stock to make the part.  This is fine, except now you will spend a great deal of money for the part and a whole lot of time in machining.   BLANK!  Here is where the novel idea comes in!  A "blank" already has an ID and an OD and is found in a number of "standard" sizes.  So you choose which blank size is closest to your finished dimensions and then machine. You can add a flange, increase your ID, turn down your OD, groove holes and much more.  You'll still have to do some machining but it will definitely be a lot less work then the bar stock and Machine Shop X will have saved $$.  Cha-Ching!
Til next time..

Good News or....Bad?

Hi All!  I just read this article on Metal Center News and I thought it was very thought provoking.  We shall see what happens in the coming months!

Copper, Brass Shipments Climbing
Copper and brass shipments continued to rally in March. Total shipments were up about 13.6 percent from February 2010 and 14.3 percent over March 2009, according to the Copper and Brass Servicenter Association, Overland Park, Kansas. This trend is in line with what the manufacturing and metals markets are experiencing overall, CBSA reports.

Total copper shipments rose slightly to just under 10 million pounds. Alloy shipments also rose sharply during the month, from just over 12 million to more than 14 million pounds.
Inventory levels also continued to rise. More than half of reporting service centers indicated their inventories were on the rise during the month, while only about 10 percent reported declining inventory levels during March.

An unexpected change in March was the number of companies reporting they still had employees on short-time or lay off. The number increased from 26 percent in February to 31 percent in March for service centers, and from 17 percent to 50 percent for suppliers. Association officials say this is a number they will continue watch closely in the coming months to determine if it’s an anomaly or indicative of something else.

What's the Difference?

One of my first official lessons as a newbie in the Metals Industry was tackling some of the “What’s the Difference” questions.  This of course could apply to just about everything in the industry but I am specifically referring to learning the difference between Solid Bar, Cored Bar and Rectangular shapes.  I had to remember terms like ID and OD, width and diameter.  (Truthfully, my head would spin!) It did seem to me that it took forever to finally be able to distinguish them apart.  But thankfully I had some patient co-workers who would repeatedly explain the difference and eventually I got it.  Now all these years later I have found I am not alone!  It is amazing how many people will call looking to get a quote on material or just need some help and they too are asking, “What’s the Difference”?  It is very comforting. 

So for my first blogpost, I figured I’d pay homage to all the “newbies” with a little lesson on what is the difference between a Solid Bar, Cored Bar and Plate shape.  And what the heck I might throw in another shape for kicks!


SOLID BAR
I'll tackle the easiest shape first - Solid Bar.  From the picture you can see that this shape is round and it's solid!  Hence the term "Solid Bar" and it's also referred to as Round Bar.  Solid Bar only has two dimensions to remember  --  a Diameter or also seen as "Ø" and a Length. 

A quick note on length - most bars in Bronze & Copper Alloys are available in any length up to 105" or 144" long.  But sometimes special arrangements can be made with a mill for longer sizes depending on your quantity. 

RECTANGLE
Next is Rectangle aka Plate.  This shape has 3 dimensions that you'll need to know.
1.) Thickness (or) Thick2.) Width (or) Wide
3.) Length (or) Long
Some people indicate these dimensions in millimeters and some in inches.  It just depends on where your from.  Also, some people won't even indicate a Length (or how long of a piece they need) but rather just supply you with a total weight (lbs) that they need.  That works too!

 CORED BAR
Then we have Cored Bar.  Oh, Cored Bar.  This definitely was the hardest for me to remember.  Some tried to give me the "Donut Analogy" but for some reason I still didn't get it.  It wasn't until I actually held a piece of Cored Bar in my hand that I got it.  And at that moment I was embarrassed. After all it's Cored!  With this shape, there are 3 main dimensions that you need to know:

1.) ID or Inside Diameter
2.) OD or Outside Diameter
3.) Length or Long
Simple enough right?  I just always got confused as to which was the OD and which was the ID.  So, I had to remember that the OD is always the larger dimension of the two.  Here's a tip:  These same dimensions are also true for Bushings (Plane or Sleeve Bushings). 






EXTRA - FLANGE BUSHING
Now for the "kicks" that I mentioned...here's a Flanged Bushing shape.  This one usually gets a lot of people.  They know to look for the ID, OD and Length of the Bushing, but they usually forget about the Flange OD & Flange thickness.  Take a look!
  The most important dimensions to pay attention to are: 
1.) ID or Inner Diameter of Bushing
2.) OD or Outer Diameter (or) Body OD
3.) Length of Bushing
4.) Flange OD (Outer Diameter)
5.) Flange Thickness
These particular bushings are available in a wide variety of alloys and they can even be self-lubricated (notice the black circle "graphite plugging" throughout the bushing) to make them easy to use and as maintenance free as possible.They are usually available off the shelf and pretty economical when ordered in large quantities.  But they can be Made to Order too using a print or drawing. 
I hope you found this post useful and informative.  I know that seeing the shapes and dimensions together was a great tool for me in understanding what was the difference!
PS:  Above photos are all courtesy Atlas Bronze and copyright protected