Center Rock manufacturers a full line of pneumatic rock drilling tools and accessories including but not limited to; Down-the ... -Hole (DTH) hammers and bits ranging from 3.5″ to 36″ (89-914 mm), Roto-Loc casing advance overburden drilling systems, and, we are the world leader in the manufacture of LP Canister drills, including the Convertible LP Drill which easily transitions from Conventional to Reverse Circulation. State-of-the-art tools, coupled with outstanding service, make Center Rock your best choice to satisfy all of your rock drilling requirements. Contact us at 1-814-267-7100 or email us info@centerrock.com for more information. read more