| Number | Part Name | Function | |--------|-----------|----------| | 1 | | Threads onto the front to protect the collet; removable for accessory changes. | | 2 | Collet Nut | Tightens around the collet to hold the bit securely. | | 3 | Collet (1/8”, 1/32”, etc.) | The split sleeve that grips the accessory shank. | | 4 | Shaft Lock Button | Locks the spindle so you can loosen/tighten the collet nut with the included wrench. | | 5 | Ventilation Slots | Allow airflow to cool the internal motor. Keep these clear! | | 6 | Variable Speed Dial | (Model 4000 only) Adjusts speed from 5,000 to 35,000 RPM. | | 7 | On/Off Switch | Slides forward to lock the tool on; push down to turn off. | | 8 | Hanger Ring | The metal loop at the rear—use it to hang the tool above your workbench. | | 9 | Power Cord | 6-foot, 2-prong cord. Check for frays here first if the tool won’t start. | | 10 | Carbon Brush Caps | Two black screw caps on the sides. Remove to inspect/replace carbon brushes. |
Unfortunately, Dremel doesn’t include a giant poster of the internal parts in the box. That’s why we’ve broken down the into simple, labeled sections—from the nose cap to the motor housing. dremel 4000 parts diagram