This ought to get you started. *Smile

The question this group has been looking for a definitive answer for is:
How did the "Letter" size drills come into being and why?

Now, a number of members in this group have made some good contributions in
support of the origin; but I don't think anyone has been able to "rubber
stamp" the quest complete.

Maybe one of your students might take up the banner.

These references come from "Metalworking Yesterday and Tomorrow" The 100th
Anniversary Issue of American Machinist
The book was given to me by Pete Noling ,who sold me my first Hurco in
1/15/'79 Seaboard Machinery Los Angeles --

Also, I'm pleased to see a group member interested in machine tool history.
*Smile I hope we have a continuing dialog.

Best regards to you all,

Stanley Dornfeld

******************************


David Wilkinson screw cutting lathe 1794

Eli Whitney Milling 1800

Simeon North pistols Milling Machine 1813

John Hall Machine developer 1813

Robbins & Lawrence American system interchangeable parts Windsor Vermont
1843
Turret lathe

Leighton A. Wilkie Band saw 1933

Sir Joseph Whitworth 1853 thread form

Joseph R Brown of Brown and Sharpe
& Lucian Sharpe Brown's apprentice 1850

Frederick W Howe 1847

William Sellers instituted the 60 degree thread form with a flat on top
equal to 1/8 the pitch. 1864

Charles H. Norton grinders 1900

Magnus Wahlstrom & Rudolph F. Bannow The Bridgeport Milling Machine 1927
Boring and Facing head

Richard F. Moore Jig Borer 1924 The Moore Special Tool Company The
highest accuracy business in the world.

And!

John T. Parsons The Father of Numerical Control 1948
*********************************

A link http://www.americanprecision.org/


end..

Errol Groff
Instructor, Machine Tool Department
H.H. Ellis Tech
613 Upper Maple Street
Danielson, CT 06239

860 774 8511 x1811

http://pages.cthome.net/errol.groff/

http://newenglandmodelengineeringsociety.org/