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; centric clamping via flat spiral; flat spiral forged in the die and heat-treated, 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 available 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 radial jaw forces acting on the workpiece at rest. The specified clamping forces are guidelines. They apply to chucks in perfect condition, 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 batch production or repair shops; 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. Additional info: The Duro-M Ø250 is a manually operated 3-jaw chuck with a flat spiral and through hole Ø76, drilling and turning jaws, bayonet mount (ISO 702-3/DIN 55027), KK 6. It is primarily used on conventional lathes for the machining of turned parts.