Ludlum Measurements offers a select range of sample planchets available in quantities of 500 pieces. The 51 mm (2 in.) diameter planchets are available in either stainless steel or aluminum and can have depths of 3 mm (1/8 in.), 6 mm (1/4 in.), or 8 mm (5/16 in.). They are also available with either a flat bottom or a bottom with concentric rings.