Rock DTH Drill bits Dia 65~253mm. 1).Soft to hard rock drilling. 2). Face:flat, concave, convex, drop center Many in stock We could supply many kinds of button bits,DTH drill bits, DTH bits,DTH hammer and drill rigs. 1). Application: water well drilling, mining drilling,rock drilling , oil drilling,etc; Working pressure : 0.5Mpa~0.7Mpa ( Low pressure) Drill diameter range : 65mm ~253mm 2).MOQ : 1 ...