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  • The Book

    I'm puzzled by Machinery's Handbook.

    I've been turning aluminum since I got my lathe, and I've learned a lot.

    Having established the form I want for a hand tool I'm turning in aluminum, I've decided to turn the final version in red bronze.

    So I went to Machinery's Handbook, for which I have both a digital subscription and a hardcopy (although the hardcopy is #27) looking for what would be different about turning bronze. I started with the question "what changes to the cutting tool do I need to make to change from aluminum to bronze?", which I thought was a reasonable question for a first timer turning bronze. Then I was going to take a look at speeds and feeds.

    And I couldn't find anything. The search function in the digital version is so slow and poor that it's virtually useless.

    I thought different metals (like bronze, or red bronze) would have their own sections, with information about machining that metal, but no.

    Is this still the premiere source for information about machining? Is there a resource that is easier to use?

    How does one use Machinery's Handbook effectively?

    Is it even worth the cost anymore?

  • #2
    I don't know about the MH questions, but the main difference I would do is to use a cutting tool with neutral rake for brass or bronze. A tool with positive rake often tends to dig in and gouge the part. You still need good back clearance behind the cutting edge. On a lathe, neutral rake is a flat, horizontal top surface out to the cutting edge, with the edge located on the part centerline.
    Kansas City area

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    • #3
      My bronze machining is mostly limited to gunmetal, one of the leaded varieties and found that it cuts easily using aluminium type of inserts and threads with general purpose laydown inserts. It does not need any lubricant. The aluminium bronzes have a bit of a reputation for being nasty to machine. This is a situation where having a variety of tooling types and a series of tests before going for the actual workpiece.
      Googling relative machining properties for metals may get answers.
      Last edited by old mart; 02-27-2022, 03:23 PM.

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      • #4
        Machinery's Handbook is supposed to be your bible, don't say it is not worth the cost. When you say you have bronze on hand, do you even know what you have? There are so many different copper alloys that the only thing they have in common is a copper content. Some of them machine easily, the other ones are not so friendly. MH gives you machineability rating for most alloys. It may not have the recommended tool geometry for each material, you develop that with experience and you can always go online.

        I have recently machined a few bushings from C932 bronze. It is a leaded tin bronze - typical bearing alloy. It machines easily with sharp tools, nothing special is required. On the other hand there are difficult to machine alloys, which may require special tool geometry.

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        • #5
          Machinery's Handbook is geared more towards the details of mechanical things than the details of metal cutting.

          For cutting bronze vs. aluminum the main differences would be reducing the cutting speed by about 25% and changing the top rake angle of the cutting tool from its positive angle to zero, or even a 1 - 2 degree negative rake angle.

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          • #6
            Originally posted by Jammer Six View Post

            I thought different metals (like bronze, or red bronze) would have their own sections, with information about machining that metal, but no.

            How does one use Machinery's Handbook effectively?
            Bronze is a family of alloys. While it would be awkward to dedicate a page to each individual alloy, they do have pages with general rules for each type of alloy. Tom_D gave the best advice, as that's normal for brasses and bronzes.

            To use the book effectively, you search for keywords, such as "bronze machineability" instead of english sentences. It still has a place in the world. If nothing else there is a lot you can learn from just reading the intro to each section. I read through mine a little at a time over a number of months. I did not memorize it, but I have a vague idea of what to look for now.

            Dan
            At the end of the project, there is a profound difference between spare parts and left over parts.

            Location: SF East Bay.

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            • #7
              I use the 25th edition. They have a section on grinding tool bits for various purposes, I imagine the angles given would extrapolate to inserts too. As for my own setup, I didn't change much when going to bronze -- just used my regular Korloy aluminum inserts on some SAE660/C932 bearing bronze. I slowed the feed rate down a bit, but thats all. It machined beautifully.
              25 miles north of Buffalo NY, USA

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              • #8
                I use dead sharp inserts on all materials and never had any problems. The radius of the insert makes a difference too. I've cut aluminum, brass and bronze with the same insert and never see any difference in finish. If the finish starts to change it's time to replace the insert, or a chip may have stuck to it. There are materials where getting a good finish is difficult, like HR and CF, cast iron. etc.
                In the past I've driven myself crazy trying different inserts that are supposed to be the "best" choice for the material but found out that dead sharp works best for just about everything.

                JL..............

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                • #9
                  If you are not doing CNC you can download older versions of it off of the Internet Archive. You can also download the American machinist Handbook which was a contemporary of the Machinery's Handbook until it closed shop back in the "40's. You can also download the Machinery's Reference Series and Data Sheets which are older single topic booklets but interesting.
                  The shortest distance between two points is a circle of infinite diameter.

                  Bluewater Model Engineering Society at https://sites.google.com/site/bluewatermes/

                  Southwestern Ontario. Canada

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                  • #10
                    I have a PDF of the 29th edition. "Speeds and Feeds" tables are under "copper alloys" and appear at page 1,036. I can't imagine that they have moved those tables around more than a few pages between editions, but my wife tells me I've already wrong 10 times just today.
                    S E Michigan

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                    • #11
                      You think what's in a book ( feeds n speeds ) for a 10,000 lb lathe is the same for a Atlas bench top ?
                      Every machine, setup, tooling is different. Books are only a starting point. Bronze turns pretty nice with carbide. Just try out a few tools and pick the one you like best for your machine. It will let you know what works best. Many machinist complained the books are wrong..... then you look at how they are tooled up ??? PFfffffffffffffff !

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                      • #12
                        Sharp tool, sufficient front clearance angle, use back rake but stone off the angle to zero just behind the cutting edge. Mark the cutter if you need to, or keep it in a section designated for brass. Make sure your cutting edge is set to the right height. Shouldn't be much of an issue. On a very small lathe you could have problems, as I have experienced. I tried once to machine aluminum bronze on the Unimat- I could not get rid of squeal and poor surface finish.
                        I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

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