Drills were designed by a surveyor.

Accord Services Corporation, Westport, Mass., released “John Henry” Carbide Surveyor’s Drills. The drills, John Henry and John Henry Jr., were designed by a surveyor and manufactured specifically for surveyors. Both drills use carbide bits for long life and fast drilling in hard rock. Both drills also feature quick change bits and will interchangeably accept bits ranging in size from 3/8" to 5/8" in diameter. The John Henry is designed for drilling holes ½" and larger. John Henry Jr. is designed for holes from 3/8" to ½". Field tests with John Henry have demonstrated that a ½" hole in granite can be drilled to a depth of 5/8" in less than two minutes.