Ingersoll-Rand's new Total Depth downhole drill (DHD) is engineered for performance and reliability. It comes in two configurations -- TD60 and TD65. Best for large blastholes and high-production rotary drills, the TD60 and TD65 drill holes from 6 inches to 6.75 inches in diameter. Total Depth models feature the Quantum-Leap air cycle system -- which allows supply pressure to be applied to the piston for 80 percent of the impact stroke -- resulting in more energy being sent to the drill bit. Ingersoll-Rand Co.