Mechanika IV. class

The reeds are made of Al alloy with hardness 95 HB. The channels are pressed by a precision cutting system. The surface of the reed is planned or ground. The reeds are made of Swedish voice steel with a strength of 1950 N/mm² with a tolerance of T3, ground to an accuracy of -40 cents of the basic tone with a head width at the rivet of 6-8 mm, with corrosion protection. The reeds are machine riveted with an air gap of 0.06 mm on each side of the tongue and machine tuned to an accuracy of +/- 5 cents.