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Drill (& gas orifice) sizes

Gordo
Gordo Member Posts: 852
I was wondering how were the "number" (80-1) and "letter" (A-Z) drill sizes created or derived. None of my old mechanics books seem to have the answer. Thanks!
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Comments

  • Not sure but

    you might try asking the folks at Anderson Forrester who make the drills I am sure they have some history. Phone number 800-745-4466. I am going tocheck and see if they have a web site.
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