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Brass, Bronze, Treasure ???

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  • Brass, Bronze, Treasure ???

    I was down at the only local scrap yard that still allows people to poke around and I found some HUGE copper-based shaft bushings. They are about a foot in diameter, 8" deep, 1" thick, and come in two parts. They are a yellowish color, but there is a hint of red. Mostly they are covered in black goo.

    Are they more likely to be brass or bronze? How could I tell which it is out in the field? I can use a file, drill, that sort of thing...


  • #2
    Hey, you are the chemist!

    But a drop of acid on brass usually removes the zinc and leaves a coppery spot. Have not seen that particularly with bronze, but it is usually more coppery to begin with.
    1601

    Keep eye on ball.
    Hashim Khan

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    • #3
      More than likely Bronze, possibly Phosphor Bronze-

      https://morganbronze.com/wp-content/...hor_bronze.pdf

      I just need one more tool,just one!

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      • #4
        Originally posted by J Tiers View Post
        Hey, you are the chemist!
        Yeah, I can come up with all sorts of fool proof methods to ID the material, even down the fractional percentages. However, I don't fancy dragging that stuff out into a scrapyard. I can also think of some definative tests, but they require multiple steps, some reagents, some glassware...

        I am hoping that there is some simple machinists test that works 90% of the time

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        • #5
          Do you have any samples of the different metals? If so, drill into each one and note the results. Then drill those dirty lumps and see if the results match any of your samples.
          I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

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          • #6
            What do you think you could use them for ? The only use I can come up with is melting for casting.
            if they are around an inch thick you can probably make cross slide or top slide replacement nuts from them.
            Last edited by 754; 02-20-2020, 02:17 AM.

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            • #7
              Originally posted by 754 View Post
              What do you think you could use them for ? The only use I can come up with is melting for casting.
              That's my idea. I am in a small group of artisans/artistes/old-farts who are about 50% finished with making a foundary for non-ferrous metals. It should be up and running by early summer.

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              • #8
                Bronze is good if you want to make a new nut for a lead screw, or making bushings. I would love some bronze. I got some brass though, 16 kg worth of a few square-ish bricks. Just building up a scrap collection.

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                • #9
                  Isn't there a 'red brass' that has a high copper content?

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                  • #10
                    Dan,

                    Probably more important than "what alloy is it?" is "can I do anything with it?".

                    Try drilling a hole in it. If it suddenly seizes and welds itself to your drillbit causing the vice to spin round and put a dint in the column of your drilling machine, then you have one of the alloys specially designed to ruin your tooling. Take it back to the scrapyard from whence it came and be done with it.

                    Ian
                    All of the gear, no idea...

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                    • #11
                      Or just get the proper tools with zero rake.

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                      • #12
                        Originally posted by Dan_the_Chemist View Post

                        That's my idea. I am in a small group of artisans/artistes/old-farts who are about 50% finished with making a foundary for non-ferrous metals. It should be up and running by early summer.
                        Very doable, those shells are large enough they could also be sectioned up on a bandsaw and yield some good sized bar stock like pieces.
                        I just need one more tool,just one!

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                        • #13
                          If they were industrial bearings, they were bronze. Brass doesn't stand up well to heavy shaft loading. We get away with using brass bushings on model engines where the loading is very low, but on full size industrial stuff, it will be bronze.
                          Last edited by brian Rupnow; 02-20-2020, 01:37 PM.
                          Brian Rupnow

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                          • #14
                            I scrounged some bearings like you describe, except about 2.5 inches where your are 8"
                            Bought them and cut them into blocks, squared them up and made bullet molds.

                            It was early in my retirement machinist phase. I didn't know there were special tools for cutting brass, so I just used some 4 flute carbide mills bought on sale.
                            My scrap must have been some nice free machining brass.

                            What my bearing was made of has no bering on what your bearing is mad of.

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                            • #15
                              FWIW
                              I have about 200 # of Bronze (mostly) from the local scrap yard for projects including casting.
                              Brass is a Zinc Alloy with Copper and is mostly valued for decorative projects
                              Bronze is a Tin Alloy with Copper and is a superb bearing material ( Tin has an extremely low coefficient of friction (COF) )
                              So the function of the scrap piece is a good guide.--- If it looks like a bearing, it most likely is Bronze
                              If it is a irregular sculpted piece or artwork, it most likely is Brass...If it has a green frost or is pure Yellow, it most likely is Brass.
                              Bronze comes in all sorts of Bronze Alloys ( Still have Tin however) The Phosphor and Aluminum alloys can be extremely hard !
                              While the Manganese Bronzes are superb for casting, so identifying these can be difficult. Have seen Phosphor Bronze 'mark" mild steel !
                              These alloys generally do not look yellow
                              Red Brass is a term given to a type of Brass with higher than normal copper content ( CS 230000) and is for water pipe fittings.
                              So look at the function first !

                              If your scrap dealer is friendly or maybe he wants to make 10 -15 $ , ask him to analyze the piece. They have $ 10,000 handheld metal identifiers they use when buying scrap and it can tell you a lot

                              Being near "The Great Lakes" ( Green Bay) , means that marine grade bronzes . ( like prop-shafts ! ) are common here, so your location also plays a roll in material at the scrap yard
                              Rich
                              Last edited by Rich Carlstedt; 02-20-2020, 10:23 AM.

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