Company Information Great is a leading supplier of premium drillig products and services o the worldwide oil and gas industry.We specialize in designing,manufacturing and marketing of various higb quality diamond drill bits for various petroleum drilling activities.Prducts series classified bycutting elements covers pdc bits,tsp bits,natural diamond bits,impregnated diamond bits.Product series classified by purpose covers diamond drill bits,coring bits,b-center bits and reaming tools while drilling.Size of various bits and special tools covers form 3-1/2" to 26",includes standard size and nonstandard size.