... durable. automatic feeding device is optional. rolling shape: rolling thread, textured, ruled, roll bars etc Model: FR-30*50 ... thread Rolling MachineScrew diameter rolled: 9-30MMPitch range: 0.5-2.5PThe maximum length of rolled screws: screws fixed 45MM ... .6, Automatic feeding device is optional.7, rolling shape: rolling thread, textured, ruled, rolling light, cross knurling, roll bars, rolling ...