Hot Extrusion of Heavy Wall Seamless Tube for Platinum Jewelry Applications
Edwin A. Crombie and Dave Arey
Johnson Matthey, Nobel Metals N.A.

After nearly four decades, Platinum resurfaced in the North American jewelry market in the mid1980's on the coattails of surging Japanese popularity. Early marketing directed at younger, less conservative consumers suggested that wedding bands would be a base from which to expand Platinum alloys into the North American jewelry markets. At that time, Johnson Matthey's predominant method of manufacture for wedding hands was to stamp ring blanks from cold rolled sheet, followed by various forming and
machining operations to produce final product. There were several advantages to this manufacturing technology

including fine equiaxed grain structure resulting in excellent ductility, hence the ability to expand / reshape inventories of fewer base sizes to a multitude of I.D. sizes, band widths and band thicknesses.

Commercially it was the manufacturing method of choice world wide. However, there were significant issues with manufacturing costs such as labor sensitivities (numerous manufacturing step procedures) and overall metal utilization, as sheet webbing and center discs outweighed finished product ring washers.

Realizing the potential market pressures for projected industry growth, JM took a critical look at this "Industry Standard Practice", and concluded that a significant improvement in manufacturing efficiency would be paramount to our future success. Therefore in 1989 we began exploring alternate manufacturing technologies

Platinum Guild International USA 2004   All Rights Reserved

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