Superior Electric ALC5491 Mini Lathe Chuck 2 Inch diameter with MT-1 and MT-2 Shank 3/4 inch MT1 style tapered shank Precision machined chuck and jaws Durable steel construction MT1 dimensions: 0.72 - 0.59 Wide | 2.74 Long MT2 dimensions: 0.49 - 0.38 Wide | 2.2 Long | Threading 0.43 diameter M25 thread.