... head3. no liable to oxidization on its surface4. high level of electrical and thermal conductivity, good plasticity and arc ... sized current contactor,starter,temperature controller,switches,etc.undercurrent contact devices,microswitches and precision instrument.Dimension: ITEMHEADDIAMETERD mmHEADTHICKNESST ... 10±2≥10±0.2R±2 electric silver contact for switch,temperature controller etc