Greetings and Question to Tim Williams

Hi Tim,
It's me, Casino from RAT. I have a question for you. Do you know
what is meant by "drop forge", "investment cast", and "cold finish"?
Sitting on my desk as a paper weight, is a 6.5-pound Folger Adam lever
tumbler maximum security jail/prison lock with a "drop forge" steel
case and "investment cast" brass keyway cylinder. Have a look my
giant "paper weight" at:
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are the advantages of "drop forging" versus "investment casting"
versus "cold finish".
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Drop forging
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Investment casting or lost wax casting:
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Errol Groff
Instructor, Machine Tool Department H.H. Ellis Regional Technical School Danielson, CT 06239
860 774 8511 x1811
Reply to
Errol Groff
^^ What Errol said. Cold finish refers to cold rolled I guess, which is where you take a piece of HRS (hot rolled stock, the S usually refers to steel, but many metals can be hot rolled), grind/pickle off the scale (oxide from being hot) and roll it cold instead. Rolling is like a continuous, lengthwise hammering process...
Drop forged is usually used on things that can a). be forged and b). need it. You could *maybe* forge a box, but it wouldn't be easy, and certainly doesn't need it. Something like that would be cast or welded from bent or cut sheet. A hammer needs strength, and is easy to forge, hence is forged. Most such tools are. Chances are, the strong parts of your lock are forged for strength.
Investment casting is usually done for pieces that need intricate detail or metals that are hard to do otherwise. Whether or not it can be sand cast in the atmosphere, inconel jet engine parts are usually investment cast, under vacuum at that (at least that's what I read). Small jewelry is easier to investment cast, and gets much better detail than other processes. Chances are, the parts in your lock that were investment cast were for detail.
Things that are simple to machine are carved from bar or flat stock, a lock barrel for instance is probably not cast but cut from rolled bar. (Due to the tolerances on such a part, it wouldn't be a raw casting, but machined anyway. Most things can be cast, but here it's like "what's the use", just drill a few holes in a piece of round stock.)
-- "I've got more trophies than Wayne Gretsky and the Pope combined!" - Homer Simpson Website @
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Reply to
Tim Williams
---------------------------------------------------- CFS vs. CRS steel Old time steel making most small shapes rounds, squares & hex were rolled to shape, but today the different shapes are cold drawn though a carbide die, hence the term cold finished steel.
Donald Warner
Don't let the facts interfere with your prejudices -------------------------------------------------------------------------
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