Abstract: An air-drive impact hammer is used to drive nails in locations where it is not possible to hold them in position with one hand and, using an ordinary hammer, drive them home using the other hand. A driver assembly has a driver shaft supported in the impact hammer, the front end surface of this shaft being a nail driving surface situated in perpendicular relationship to the longitudinal axis of the driver shaft. An intermediate ball keeper sleeve is concentrically and slidably mounted around the driver shaft, and an outer sleeve is concentrically and slidably mounted around the ball keeper sleeve. Four detaining ball receiving openings extend radially through the ball keeper sleeve on radial axes while lying in a common plane perpendicular to the longitudinal axis of the driver shaft. Nail head detaining balls are situated in each of the ball receiving openings.