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<p>[QUOTE=&quot;jaceravone, post: 497599, member: 9474&quot;]<font face="Arial"><p style="text-align: left">[FONT=Arial, Helvetica]<font size="2"><span style="color: #000080">After heat treatment and annealing, <b>burnishing, polishing, descaling and pickling is employed to make the surface of the coin blank brighter, remove any surface scaling</b> or discolouration and in some cases apply a minute amount of lubricant to assist in coining. </span></font></p></font></p><p style="text-align: left"><font face="Arial"><font size="2"><span style="color: #000080"><br /></span></font></p></font></p><p style="text-align: left"><font face="Arial"><font size="2"><span style="color: #000080">This process is carried out in a Vibratory or Centrifugal Finishing Machine that tumbles the coin blanks with a mixture of stainless steel balls and other media like ballcones and special chemicals, which etch and polish and brighten the surface. At times this process is preceded by a run in ceramic media.</span></font></p></font></p><p style="text-align: left"><font face="Arial"><font size="2"><span style="color: #000080"><br /></span></font></p></font></p><p style="text-align: left"><font face="Arial"><font size="2"><span style="color: #000080">After burnishing in stainless steel media, the coin blanks are dried by passing them through a hot air drier or by tumbling them with heated corncob to remove all water marks and to prevent any subsequent tarnishing or atmospheric oxidation. The annealed, burnished and dried blanks are stored ready for coining.</span></font></p><p></font><p style="text-align: left"> [FONT=Arial, Helvetica]<font size="2"><span style="color: #000080">The burnishing operation is also employed after stamping of the coins.</span></font>[/FONT]</p> <p style="text-align: left">[/FONT][FONT=Arial, Helvetica]<font size="2"><img src="http://www.steelmedia.com/steel-burnishing-media_files/vbcomponent.jpg" class="bbCodeImage wysiwygImage" alt="" unselectable="on" /></font></p> <p style="text-align: left"><font size="2"></font>[/FONT]<font face="Arial">[FONT=Arial, Helvetica]<font size="2"><span style="color: #ff0000">Ball Burnishing Machine with</span></font></font></p> <p style="text-align: left"><font face="Arial"><font size="2"><span style="color: #ff0000">Inox, Stainless Steel Balls</span></font></font>[/FONT]</p> <p style="text-align: center"><br /></p><p>[/QUOTE]</p><p><br /></p>

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