Short description: The DURO-M is a manually operated chuck with a flat spiral and through hole. It is primarily used on conventional lathes for the machining of turned parts. Technical features: Chuck body (as well as all other components) made of steel; centrally clamped via flat spiral; flat spiral forged in the die and highly tempered, thread flanks ground on both sides; jaws ground for concentricity in the chuck; factory-determined zero play as accuracy drive; the maximum permissible speed is set so that at maximum clamping force and when using the heaviest associated jaws, one-third of the clamping force remains as residual clamping force. The jaws must not protrude beyond the outer diameter of the chuck. The chucks must be in perfect condition. Furthermore, the regulations according to DIN 6386 Part 1 apply. Clamping force according to DIN 6350: The clamping force is the sum of all jaw forces acting radially on the workpiece while at rest. The specified clamping forces are guideline values. They apply to chucks in perfect condition that are lubricated with Röhm grease F80. Delivery includes: Chuck, chuck key, jaws. Areas of application: Conventionally clamping horizontal and vertical lathes as well as milling machines, rotary tables, and dividing heads. Mainly used in single or small series production or repair workshops. Clamping of rotationally symmetrical parts for turning and milling operations. Advantages: High concentricity accuracy up to 0.02; jaws are fundamentally blued; minimal interference contour; high force transmission; drip edge for coolant. Further information: The Duro-M Ø250 is a manually operated 4-jaw chuck with a flat spiral and through hole Ø76, drilling and turning jaws, cylindrical mount (DIN 6350, Form A), ZA 200. It is primarily used on conventional lathes for the machining of turned parts.