huangyhg

small pin manufacturing
greetings,
i need to manufacture a pin that is much like a pin gage used for measuring. the pins need to be about 3" long and vary in diameter from 1mm down to .2mm. the ends of the pins must be perfectly flat so that the pin would balance if stood on end.
what material(s) and manufacturing process would you recommend? a pin gage is the exact design, i just need to make sure the bottom is flat so that it will balance on its end.
i appreciate any assistance.
thank you,
eng-tips forums is member supported.
first, i'd try to buy 'em from, e.g. torrington.
then i might buy a ... i forget what they're called, but diemakers use them to make ejectors. maybe "ejector pin blanks"; they look like a very long dowel pin, but one end is headed, like a flat head screw with no slot or recess. they're very hard and very straight.

mike halloran
pembroke pines, fl, usa
thanks for your thoughts. i have purchased some pin gages and they are what i am looking for, but i don't have a way to verify if they are flat on the bottom because they are so small. i wonder how they manufacture them because that same process would probabaly work for me.
well, you can check for square ends by standing them on end, exactly as you say, on a level surface plate, at night and away from traffic.
you should be able to check for flatness, not the same thing, with an optical flat and some magnification and some patience.
or chuck 'em in a collet and spin 'em in a "spin-dex" fixture while indicating the end with a "tenths" indicator and a point with a small radius.

mike halloran
pembroke pines, fl, usa
in small quantities, the parts would be machined from bar/wire. for large quantities, the parts would be cold formed.
regards,
cory
depends on how many. clamp and grind comes to mind. cut them from straightened wire, hold them and grind the ends. alternatively fixture them in a block and grind across the top and bottom.
how many and how flat comes to mind as essential questions. how flat as in perpendicular to the side measured in degrees? how flat as in surface smoothness?

thomas j. walz
carbide processors, inc.
these pins are 3 inches long, .2mm (.008")d and will "balance" on it's end? i would like to see a picture of this being accomplished.
by my reckoning, if one side is 70 nanometres longer than the other, it falls over. that's some serious machining (but not impossible). how flat is the surface table you're measuring it on? you probably need an optical flat to test this. good luck!
would an optical comparator and optical micrometer be useful in measuring, calibrating and inspecting your pins?
your real problem may be the inspection process. if your test is to stand the pin on end, the reference surface must be perpendicular to the local gravity vector,to less than 0.07 degrees. inclinometers for this are available.

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