TOPEX Chuck Holder Flange TOK.3244 FI 250/8 for DIN 55027 Size 8 Spindle, 250 mm

Mounting a lathe chuck securely to the spindle nose can be a challenge when the chuck's backplate doesn't match the machine's spindle interface. This TOPEX chuck holder flange solves that mismatch by providing a precision-ground adapter that bolts directly onto a DIN 55027 size 8 spindle nose and accepts a 250mm chuck. It eliminates the need for custom machining and ensures concentricity for accurate turning operations.

Who is it for

This flange is intended for machinists, toolroom technicians, and lathe operators who need to mount a 250mm chuck (typically a 3-jaw or 4-jaw) onto a lathe with a DIN 55027 size 8 spindle nose. It is suitable for both professional workshops and serious hobbyists using machines with this standard spindle interface.

Main features

• Precision machined from high-grade cast iron for rigidity and vibration damping.
• Conforms to DIN 55027 (ISO 702-1) size 8 spindle nose standard for direct fitment.
• Flange outer diameter of 250mm matches common chuck backplates.
• Eight spindle mounting holes on a 171.45mm PCD with M16 bolts for secure attachment.
• Typical chuck mounting pattern: three holes on a 210mm PCD for 3-jaw chucks (verify your chuck).
• Ground and machined faces ensure accurate alignment and minimal runout.

Specifications

• Product type: Chuck holder flange
• Application: Lathe spindle mounting
• Spindle nose standard: DIN 55027 (ISO 702-1)
• Spindle nose size: 8
• Flange outer diameter: 250 mm
• Spindle mounting holes: 8
• Spindle mounting hole PCD: 171.45 mm
• Spindle mounting bolt size: M16
• Chuck compatibility diameter: 250 mm
• Chuck mounting holes (typical): 3
• Chuck mounting hole PCD (typical): 210 mm
• Material: High-grade cast iron
• Overall thickness: 40 mm
• Spindle bore diameter: 85 mm
• Finish: Precision ground and machined
• Mounting method: Direct spindle mount
• Compatibility: Suitable for Bison-Bial and other standard lathe chucks

Tips

Always verify the spindle nose size and chuck mounting pattern of your lathe and chuck before ordering. For 4-jaw chucks, the mounting hole pattern may differ; consult your chuck's documentation. Use the appropriate torque when tightening mounting bolts to avoid distortion.