The DEWALT 7/16 In. Quick Change Mandrel (1-1/4 In. to 6 In.) is part of a full range of hole saw mandrels that was thoroughly tested through over 15,000 cycles on a variety of jobsites to ensure that they work for you in real world situations. Hole saws will never lock to this mandrel because its spring-loaded collar automatically engages drive pins. Double set screws with a recessed combination head make centering bit changes quick and easy, so you never have to take your mind off the job. DEWALT standard and quick change mandrels are the right choice for any professional hole saw application.