Professional Jeweler Archive: Lathe Leeway

October 2001

Professional Bench/Tool Tips

Lathe Leeway

Bezel-setting round brilliants in tubes

Tom Weishaar is not a watchmaker, but he regularly uses a watchmaker’s lathe for various jewelry-making procedures, including setting gemstones. Here he sets a 0.50-ct. round brilliant diamond in a 14k yellow gold tube.

Weishaar places a thick-walled 14k tube with an inside diameter of about 4.8mm in the lathe. The diamond he’ll set is 5.12mm. He spins the tube and holds a #4 cut flat barrette file against the top to flatten the outside surface.
Next he selects and places a 5.09mm low-speed setting bur in the opposite chuck of the lathe. He introduces the stationary bur into the top of the spinning tube and cuts a bearing for the diamond. Then he performs prefinishing steps, including polishing inside the bezel with a cotton swab and semichrome polish. Now he can set the diamond.
Weishaar uses a highly polished piece of flat steel to gently apply pressure to the top of the bezel while the tube is spinning, burnishing metal over the diamond to secure it in place.
With the tube spinning, he bright-cuts the inner and outer portions of the bezel.
Using a standard jeweler’s saw, he cuts away the bezel from the tube.
Finished and ready to be picked up.

By Mark B. Mann, Director of Trade Programs, Jewelers of America

Featured Application by Tom Weishaar, JA® Certified Master Bench Jeweler™, Underwood’s Fine Jewelry, Fayetteville, AR

Photographs courtesy of Jewelers of America and Underwood’s Fine Jewelers
© 2001 Jewelers of America

Copyright © 2001 by Bond Communications