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View All Poly Chain® GT™2 Sprockets


Product # 78963307

Strong, durable sprockets designed for use with your Poly Chain® GT™2, Poly Chain® GT™ or Poly Chain® GT™ Carbon™ belts.

  • Full split in bushing allows for easy installation and removal
  • Poly Chain® GT™2 Sprockets keep overhung load below manufacturers’ recommendation
  • Precise sprocket design produces positive, press fit to shaft
  • Precision manufactured and static balanced
  • Re-work services have turnaround time
  • Smaller, narrower sprockets save shaft space, keep the load closer to bearing and extend life of reducer
  • Sprockets are precision manufactured and static balanced
  • Warning: Do NOT use these sprockets with rim speeds in excess of 6,500 fpm
  • Product Details
    Part # 8MX-25S-12 REBORE  /  8MX25S12
    Product # 78963307
    Description 8MX-25S-12 REBORE
    UPC 770075504924
    Pitch 8 mm
    Number of Grooves 25
    Width 12 mm
    Pitch Diameter 2.506 in
    Rebore true
    Bore Range Min 0.5 in
    Bore Range Max 1.5 in
    Material Gray Iron
    Profile GT
  • Application
    Markets/Applications Use with Poly Chain® GT®2, Poly Chain® GT® or Poly Chain® GT® Carbon™ Belts.
  • Notes
    Belt Notes Orders must be placed through the Made-to-Order Metals team and should not be placed on PowerPro®. Rework applies only to plain bore sprockets. When ordering, specify the part number and rework needed. Rework options are as follows: BTS = Bored to Size and includes Standard Keyway and set screws. PB = Plain Bore. No Keyway. No Set Screws. KWY = Keyway only. SS = Set Screw only. To order, contact the Made-to-Order Metals Team 800-709-6001 or email
    WARNING: Do NOT use these sprockets with rim speeds in excess of 6,500 fpm.
  • Packaging details
    Customer Pack
    Weight (lbs.) 1

The Industry's Best.

With patented, carbon tensile cord design for high-torque, low-speed drives, Gates® engineers were the first in the world to incorporate a high fatigue-resisting carbon fiber tensile cord into the belt, which is made of a new polyurethane compound. Consequently, Poly Chain® GT™ Carbon™ quickly became the most powerful line of synchronous belts on the market, providing a maintenance-free, energy saving, and environmentally friendly operation, offering an excellent alternative to roller chain and gear drives.

Metals Made to Your Application Specifications.

With Gates® MachineWorks services, our product application experts work with you or your facility manager to customize drive components in a variety of bores, styles, materials, and finishes for your non-standard and prototype power transmission and belt drive applications.