... quality of raw material through special heat treatment ,especially, tungsten carbide of tapered button bits are from Boart long year, widely ... requirements on delivery design, number of buttons is 4, 5, 6, 7, 8 , 9, 7 buttons is very popular for hold held ... and button bits.Product featuresPremium designs and steel and premium tungsten carbide insert grade T6 supplied by Boart Long year, Offers industry ...