Thursday, March 9, 2017

March Plate Madness!





Hello everybody!
 
It's that time of year again...March Plate Madness! While one doesn't typically associate Bronze Plate with the same type of hysteria that Basketball creates, for some of us, it's pretty exciting!  Of course, if Bronze was still made of Copper & Arsenic then we might find some customers truly experiencing madness. But luckily humans wised up and replaced that Arsenic with Tin!  

     So why is Plate so neat?  In my personal opinion, I think that of all the Bronze Shapes (i.e. Cored Bar or Solid Bar) plate is the most versatile in both Method of Manufacture & Secondary Processes.  Like I said, this is just my personal opinion so if I have offended anyone, my apologies.

    The plate that I usually come in contact with is made from one of the following methods of manufacture: Continuous Casting, Sand Casting, Hot Rolled, Cold Rolled and/or Forged.  And check this out... the method of manufacture depends on the Alloy, Material Specification, size range needed, quantity and lead time.  Crazy, right?!
Please join me as I jump into the wonderful world of Plate and explore the amazing Secondary Processes that can be done with it. In this weeks post I will detail the following list of topics.

3 "D" Saw cutting
Ground Plate = less time = less $ lost
The Unique Diamondized Naval Brass Plate
Graphite Plugging
Water Jet Cutting
Decorative Purposes

I hope you will find this as fascinating as I do and join me in the love for Bronze Plate!
-Melissa

3 “D” Saw Cutting
Sure a lot of companies can saw cut and yes the cutting itself is neat to watch.  But it just so happens that Atlas Bronze is one of the only suppliers that can Saw Cut a Big Block of bronze plate on all (3) sides:  thickness, width and length.  Where in the past, a customer would have to Sand Cast a piece to a non-standard thickness or have several hundred (or even thousand) pounds run in a mill, depending on the alloy -- we eliminate that need by offering this specialty cutting.

For example:  Take C93200 Plate -

What if you needed a 1.125" thick x 2" wide x 40" long BUT the mill only has standard sizes that they can offer.  They would offer you the next available size up -- 1.25" thick x 2" wide.......

Yes this can work but it's a lot extra material left over from milling that plate down.  A lot of extra material = more $ spent on the bar(s) + all that extra time invested in the milling process. 

This is where Atlas Bronze comes into play!

We take one of our Big Blocks-- in C93200 we have (2) different sizes to choose from:  4" thick x 12" wide (or) 6" thick x 8" wide.  We take the block and then cut it on ALL (3) sides to get the thickness that the customer needs.

So the customer winds up with the desired dimensions of:  1.125" thick x 2" wide x 40" long.






Ground Plate = less time = less $ lost
This is where we take C93200 (Bearing Bronze Plate) or C95400 (Aluminum Bronze Plate) and grind it top & bottom to a +/-.002 on the thickness.  Why does this matter?  Because it reduces the amount of time one needs to mill or grind a piece down -- less time to machine = less money wasted.  Grinding Plate down is just a plain smart secondary process for the machine shop and end user alike. 
Although I only mention C93200 & C95400, we can actually surface grind any of our Plate alloys that are in stock.


The Unique Diamonized Naval Brass Plate
As far as I know there is only (1) machine in the world that can produce the "Diamonized Finish" This is one of the "prettiest" alloys we stock. It is stunning to look at and it truly does look like you are staring into a mirror.  That aside, its functionality is impressive as well.  It has excellent wear properties, corrosion resistance and softness.  It has a gauge tolerance of +0.000, -0.004 and much more!

Graphite Plugging
This secondary process, which is also considered Self Lubrication, is great when standard lubrication is impractical, including heavy load, high temperature applications. You do wind up spending a bit more money by having the plates plugged but now you have permanent lubrication built into the part.  Thus eliminating the need to stop the machine and re-apply lubrication. 

Less Time = More Money!


Water jet Cutting
I love the idea that you can take a rectangle sheet and make them circles.  Okay this is hokey but it kind of reminds me of crazy Spirograph toy that I used to play with as a kid (ahh…who am I kidding, I still love to play with them!).  So why is Water jet cutting a great secondary process, take a look:


Water jet cutting has been around since the early seventies but was of little value to engineers as then it was only capable of cutting thin gasket and foam materials. Abrasive jets extended the concept about 10 years later.

Both technologies use the principle of pressurizing water to extremely high pressures, and allowing the water to escape through a very small opening (typically called the "orifice" or "jewel"). Water jets use the beam of water exiting the orifice (or jewel) to cut soft materials like confectionery and foam etc. but are not effective for cutting harder materials.  Abrasive jets use that same beam of water to accelerate abrasive particles to speeds fast enough to cut through much harder materials.

We frequently get requests for circles in Brass Plates calling for thicknesses that otherwise couldn’t be achieved in any other fashion, except to water jet.  


Decorative Purposes
Over the past few years we have supplied plate (all different alloys) that would wind up being included in some of the neatest places. An example of this would be we supplied plate that would be polished, water jet cut and then installed at the Main Entrance at Macy's Herald Square. (see below)

© 2017 Macys.com is a registered trademark. All rights reserved.

We have supplied brass sheets that would be the decorative sheets to escalators and elevators, window and building facades, (such as the Novartis Building in New York) and much more.



Thanks for taking the time to learn a little bit with me.  Until next time, my metal loving friends...






DISCLAIMER:  While Maranatha Now, Inc. dba Atlas Bronze strives to make the content on this blog as informational and educational as possible,  Maranatha Now, Inc. dba Atlas Bronze makes no claims, promises, or guarantees about the accuracy, completeness, or adequacy of the contents of this blog, and expressly disclaims liability for errors and omissions in the contents of this site.

Tuesday, February 28, 2017

An Atlas Bronze Project Re-Visited: Ground Plates

An Atlas Bronze Project: Ground Plates

Since I am advertising Ground Plate this week, I thought I'd re-visit one of our previous Blog posts. 

Back in 2015, a customer of Atlas Bronze came to us and requested ground plates from our stock. We were thrilled because ground plates are Atlas Bronze's specialty products that we make in house!

Our customer wanted ground plates to create award plaques for the Des Moines Concours d’Elegance 2015, a premier automotive exhibition held at the John and Mary Pappajohn Sculpture Park in September. It is an invitation-only exhibition of more than 100 vintage and classic motor vehicles, selected to celebrate the fine art, design evolution and amazing innovations of motor vehicles through the years, as well as the talented designers and engineers who created them.

The award plaques that were created were designated for People’s Choice and Best of Show. You can watch the video of the exhibition here, and at the end you will see them award with the winner!


Our ground plate material is a cost saver and time saver. Since the material is stocked in a ground condition +/- .002 on the thickness (we aim for +/- .000 so if you need a closer tolerance we will mic material upon request). Our bronze flat stock is machined from continuous cast, fine grain plate. Our bars are supplied ground top & bottom. 

A benefit of the ground plates is that there is no milling or grinding necessary on the top or on the bottom – it’s already done for you! No need to block it in, taping it down or tow clamp it anymore!

It was truly a neat experience to see one of our guys actually ground this. Watch the reveal video here!


Tuesday, January 10, 2017

Casting Options: Methods of Manufacture







When you begin a project, there may be a perfect vision in your head, but to get it to the final stages there are a lot of decisions that need to be made to achieve the highest quality of product.


Over the years Atlas Bronze has acquired the keen knowledge of how your material is made, the lead time for the material and the ultimate cost will depend on the some of the following factors:

  • Desired Alloy
  • Specification (if noted)
  • Size Range
  • Quantity
  • Lead time needed
Each alloy group has unique methods for how the material is made or cast and we take into account for all the factors in determining the best method to offer a customer.  This is possible because we have over 100+ years of combined experience in our Sales Group. 

The best way to help you determine the best fit for your needs would be to CONTACT US by either email or call 1-800-478-0887.
Some of the most common methods of casting for Bronze Alloys are as follows:
Sand Casting

Sand casting is probably the oldest method in practice. In this process the mold is prepared using sand or silica and the molten liquid metal is poured into it. The mold is made of two parts, the cope and the drag. A wooden pattern is placed between these two parts, called the mold cavity. The liquid metal enters here and casts itself. The shape of the mold cavity is similar to the final object after the refining
















Centrifugal Casting


The Centrifugal casting process uses a mold which is fixed to a motor on an axis to rotate it at high speeds. The speed of rotation depends on the metal to be cast and the shape required. This method is mainly used for the production of cylindrical components like pipes. As the motor rotates, the metal gets pushed towards the outer walls of the cast and solidifies. The centrifugal process is unsuitable for making linear-shaped and dense objects.






Continuous Casting


Continuous casting, as the name implies, converts molten metal into a continuous moving ingot shape with a rectangular or round cross section. Time, energy, and labor are saved. Generally, a water-cooled mold is employed, receiving molten metal in one end and delivering a continuous solidified product out the other. The molds can be vibrating or moving, slow or fast.









          Atlas offers high quality Sand Casting, Centrifugal Casting, and Continuous Cast products at competitive prices and great lead times.  Your alloy, specification or application might indicate the part needs to be made as any one of the listed methods.   Speak to one of our Sales Representatives to determine if your application should be made as a Continuous Casting product.

For more information or to see what else we could do to help, please visit our website at www.atlasbronze.com

Wednesday, December 28, 2016

Bearing Design Guide: Chapter Twenty-Three: CBBI Manual Bearing Procedure and Notes




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1. Identify the particular application from Fig. 6 through 10 in the CBBI Manual.

2. Pick up the recommended value for M from the type of machinery application.

3. A= M(squared)W I D(squared)Z N

 W = load in pounds
 D = diameter of shaft or bush ID
 Z = absolute viscosity ( centipoises)
 N=RPM
 A = characteristic number

a. Assume an operating temperature

b. Z can be determined for the lube at assumed temperature T(2)

c. A fair approximate of lubricant temperature rise can be made.
Forced feed or pressure lubrication, temperature rise will average between 5 and 10 degrees F, if less oil is supplied bearing will run hotter, thus for other lubricating techniques, such as oil bath, splash feed and ring oiling, lubricant may rise from 1 0 to 1 00 degrees F.

d. After substitution, if "A" falls in the range of .0005 and .50, practical full-film lubrication is possible.

ANALYSIS:
A large value for "N' indicates a heavily-loaded or slow-speed bearing.

Conversely, light loads and high speeds, a very low "A" number will be obtained.

With a light load or no load, eccentricity ratio "e" will be zero and centered.

As the load increases, the journal moves eccentrically.

While eccentricity "e" is increasing, the minimum film thickness (Ho) is decreasing.
Ho = c-e = c (i-e)

If the load becomes great enough, the journal may eventually touch the bearing for this condition:
"e" = c, (Ho) = 0.

Once the bearing characteristic number is determined, a suitable length for the bearing can be determined.


LUBRICATING CONDITIONS

Hydrodynamic Mode:
1. Surface velocity in excess of 25 FPM
2. Coefficient of friction is .001-.005
3. Proper viscosity of lube
4. Proper lube flows
5. Proper design methods

Mixed film/Lubrication Mode:
1. Surface velocity in excess of 10 FPM
2. Coefficient of friction .02-.08
3. Journal BRG goes through all three modes

Boundry Lubrication Mode:
1. Generally slow rotary motion, less than 10 FPM
2. Oscillating motion
3. Coefficient of friction .08-.14
4. Generally grease lubricated

Press Fits or Shrinkage Fits:
1. Generally . 00 1" minimum press fit should be sufficient for ODS up to 3" OD
2. Adjust press fit for bearings through 6" OD to about .002 minimum
3. Following a press fit or shrinkage fit, the bearing ID will close in on the ID by 100% of the press fit allow. Heavier wall bearings will average 60 to 80% close in based on the interference fit allowance.

Bearing Retention Methods:
1. Press fit or shrinkage fit
2. Set screws
3. Woodruff keys
4. Bolted through flange
5. Threaded/screwed bearing

Clearance Allowances:

1. Machined bearings with ground journals for use in steam turbines, generators, etc., usually have a running clearance of. 001 per inch of shaft diameter.
2. Clearances of .0015 through .0035/ inch of diameter are used for grease and solid lube conditions.


Thank you for joining me on this journey.  Although we are done with The Bearing Design Guide, don't be sad.  I have more exciting things coming in the New Year!

That's all for now.  Until 2017 my metal loving friends! 


REFERENCES
Mechanical Bronzes (Brass World & Platers Guide, March 1924)
Development in Centrifugal Casting (Metal Industry, Aug. 1939)
Wear and Surface Finish (Gisholt Machine Co. 1947)
Plain Bearing Recommended Practice (AISI April1951)
·Bearing Materials and Properties (Machine Design March 1966)
Cast Bearings (Machine Design March 1966)
The Science ofTribology (CDA London Engineer 1969)
Plain Bearing (Machine Design Jtme 1970)
How to Install Plain Bearings (Power Transmission Nov. 1970)
Plain and Premounted Sleeve Bearings (Machine Design June 197 4)
Copper Alloy Casting Design (CDA United Kingdom)
Boundary Lubricated Sleeve Bearings (Battelle, Columbus, Ohio)
Wear of Cast Bronze Bearings (Incra Aug. 197 6)
Physical Properties of Copper Alloys (Casting Engineering 197 6-77)
Wear Properties of Heavily-loaded Copper-based Bearing Alloys
Power Transmission Design (1994)
When Designing Journal Bearings (Bruce Dunham, Sun Oil Co.)
Bearing Design & Applications (Wilcox, Booser, McGraw-Hill, 1957

Thursday, December 22, 2016

A Christmas Story Moment "Stuck" In History

 

Stuck? Stuck?! STUCK! STUCK!  Come back! Don't leave me, come back!
           Who doesn't remember the iconic scene from the movie A Christmas Story where Flick, while surrounded by his instigating school pals in the school yard at Warren G. Harding Elementary School, got his tongue stuck to a pole. In my opinion, its one of the best scenes in the movie.

          Apparently I'm not the only one that thinks its a classic. The small town of Hammond, Indiana where the movie was filmed and where the incident took place felt it needed a permanent reminder of the classic.

          In 2013, on the films 30th anniversary a bronze statue was erected capturing the moment perfectly.  The statue was brought to its new home in a shipping crate appropriately marked with "Fragile" just like Ralphie's fathers "major award", the famous Leg Lamp. A grand Celebration was had and who better to debut the statue was none other than A Christmas Story's own Flick, also know as actor Scott Schwartz.

Scott Schwartz having fun with the statue
      
          The statue sits in front of the Welcome Center in Hammond, Indiana just off Interstate 80-94.  Travelers are encouraged to visit, but might not want to try and re-enact the famous scene because this flag pole is made of metal and you could very well get your tongue stuck if you try.

          So...take a night this holiday season and watch A Christmas Story, or if you're feeling adventurous, take a trip to visit the now famous landmark.

         I triple dog dare you...


        

Monday, December 19, 2016

Bearing Design Guide: Chapter Twenty-Two: Soldering, Brazing and Welding of Bronze Alloys


          Copper-based alloys, like other metals, occasionally require joining by soldering, brazing and welding. The following is intended to assist in those procedures.
       
          In soft soldering, the low melting solders of tin and lead, in varying proportions, are used to join bronzes at relatively low temperatures well below the melting point of the bronze alloy or its lead content (if the lead content is 3% or less). The solders most generally used are the 60 tin and 40 lead solder which melts at 374 degrees F and the 50 tin and 50 lead solder which melts at 477 degrees F.  You can see a great detailed example of this here.

          Soldering is used to provide a convenient joint that does not require any great mechanical strength. It is used in combination with mechanical staking, crimping or folding and used to seal against leakage or to assure electrical contact.

          Fluxes for soldering: Soldering requires the metals being joined to be clean and fluxes clean the surface by removing the oxide coating present, keep the area clean by preventing formation of oxide films and lower the surface tension of the solder by increasing its wetting properties.




          Rosin, tallow and stearic acid are mild fluxes but are not too effective in removing oxides present. Zinc chloride and ammonium chloride used separately or in combination will remove oxide films readily, however, this flux residue must be removed or neutralized to prevent their corrosive effects. Washing with water or with commercial water soluble detergents will neutralize any further corrosive effects.

          Methods of application: Soldering can be done with a soldering iron, a torch, electric induction or resistance heating. There are no special techniques used to solder except the usual precautions of cleanliness and fit of mating surfaces. The advantage of soldering is a low-temperature process, good manual application, no fusion of parent metals, and, therefore, no warpage. It is applicable to most copper-based alloys (with less than 3% lead) with minimum finishing requirements being necessary.

          Brazing is a method of joining two metals through the use of heat and a filler metal below the melting point of the metals being joined. Brazing creates a metallurgical bond between the filler metal and the surfaces of the two metals being joined.



          Again, here in order to obtain a sound joint, the surfaces in the join and around it must be free from oil, dirt and oxides. Cleaning can be achieved by chemical means such as using trisodium phosphate, carbon tetrachloride and trichlorethlene for chemical method and the use of filing, grinding, machining or sand-blasting for mechanical means of cleaning.

          Fluxes are used mainly to prevent formation of oxides and to remove oxides from the base and filter metals and to promote free flow of the filler metal.

          We're in the home stretch.  Only ONE more chapter to go!  Be sure to check out the Blog on Thursday the 22nd for a special Christmas edition of Metalchic.

That is all for today...Until next time, my metal loving friends!

Next Up: Chapter 23: CBBI Manual Bearing Procedure and Notes

Monday, December 12, 2016

Bearing Design Guide: Chapter Twenty-One: Corrosion Resistance Of Some Bronzes


We are going to continue with our chapter, but first a little announcement...



And now onto...Bearing Design Guide: Chapter Twenty-One: Corrosion Resistance Of Some Bronzes


          Corrosion is defined as the eroding of a metal as a result of a reaction with its environment, or exposure to various liquids or gases.

          Some metals and alloys are naturally resistant to certain corrosive environments. The product of a corrosive film which forms when metals are subjected to corrosive attack protects them from speedy damage by virtue of this protective oxide film.

          Corrosion can occur in bronzes as a result of slow dissolution of copper and copper alloys either because no protective film is formed or because as fast as a film is formed, it enters into solution in the corroding medium.

          Outdoors, copper and copper alloys develop a relatively protective skin of sulfides, oxides or soot. The sulfides form as a result of a reaction with sulfuric acid in the atmosphere and oxides as a result of a reaction with oxygen in the air. These reactions speed up in humid and rainy climates. They would cease entirely in the absence of water.

          Galvanic corrosion is caused by compounds which are electrical conductors when in solution in water and are known as electrolytes. The ions in these electrolytes are ever ready to conduct electricity if an anode (the positive ion) and cathode (the negative ion) of any type are present.

           Solutions of carbon dioxide, sulfur dioxide, oxygen, chlorides and fluorides are condensed or precipitated from the atmosphere. When a metal is to be used where there is an electrolytes as in sea water, the coupling of metals must be close together in the EMF series; to reduce the tendency to corrode the least nobler (cathodic) material.

          Galvanic corrosion often can be prevented by separating the less noble material by insulating it with rubber or synthetic resins.

           Although aluminum alone as a base material possesses good corrosion resistance to dry atmospheres, it actually corrodes very rapidly until a surface film forms. The surface film arrests further action to sea water, many fresh waters, chemicals and foods.

          This oxide film is extremely thin and, when damaged or scratched, corrosion will reform another thin film. Aluminum, therefore, depends on the resistance of the formed oxide film to attack rather than to the base metal.

          If aluminum is coupled with a copper-based alloy as bronze in a wet atmosphere, such as in marine environments, corrosion of the aluminum will continue unabated and would be an unfavorable galvanic couple. However, in a dry atmosphere, there is no precipitable galvanic action encountered.

          The high-leaded tin bronzes, leaded tin bronzes and tin bronzes have poor resistance to most acids but good resistance to sea water, fresh water, gasolines, fuel oils, alcohols, Freons and many other mediums. But it is recommended that the copper alloys be tin-coated or plated.

          For the most corrosive resistant alloys, the aluminum bronze alloys offer the greatest protection. The aluminum bronze alloys are used for their strength primarily and extensively used in general outdoors, marine service and exposure to many acids.

Galvanic Corrosion On Propeller


          A brief list follows showing the acceptable and non-acceptable exposure to various corrosive medium by aluminum bronzes.






          In the case of manganese bronzes, which contain less than 80% copper, zinc is selectively removed from the alloy by most acids when diluted in water. Manganese bronzes can be used for marine applications, water pump rotors and in sea water.



That's it for today.  Until next time my metal loving friends...

Next Up: Chapter 22: Soldering, Brazing and Welding Of Bronze Alloys