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Aluminium jaw coupling hub, 25.4 mm diameter, 35.3 mm long, 8 mm clamp bore

Ruland Manufacturing

Ruland Manufacturing MJC25-8-A Jaw Coupling Hub 8 mm Bore

SKU CH-0ZDT-N1W6N

Metric aluminium jaw coupling hub with 8 mm clamp-on bore, 25.4 mm diameter and 8,000 RPM rating

  • Metric jaw coupling hub with 8 mm clamp-on bore
  • Aluminium MJC25 hub rated to 8 000 RPM
  • Curved jaw profile provides fail-safe operation
  • 4 mm outside diameter fits compact drives
  • Bore tolerance +0.05 /-0.00 mm ensures precise fit

Jaw Coupling Hub MJC25

The Ruland MJC25-8-A is an aluminum jaw coupling hub with an 8 mm clamp-on bore for metric shafts. It suits machinery builds that need a compact, fail-safe connection between motor and driven equipment. The curved jaw profile works with standard elastomer spiders to damp vibration and tolerate misalignment. Buyers who need a larger bore or a keyway instead of a clamp must choose a different hub.

Thermals and Power Draw

The hub itself generates no heat and draws no power; it transmits torque mechanically up to 8,000 RPM. Noise and temperature depend entirely on the spider material, alignment quality and the driving motor. Full bearing support on both shafts is required to keep vibration low and prevent premature wear.

Build Integration

The hub measures 25.4 mm outside diameter and 35.3 mm overall length with an M3 clamp screw. It fits shafts held to a tolerance of +0.000 / -0.013 mm and a bore tolerance of +0.05 / -0.00 mm. The clamp-on locking frees the shaft from keyway machining but demands precise shaft diameter and clean surfaces. California Proposition 65 warnings apply.

Highlights

  • Metric jaw coupling hub with 8 mm clamp-on bore
  • Aluminium MJC25 hub rated to 8 000 RPM
  • Curved jaw profile provides fail-safe operation
  • 4 mm outside diameter fits compact drives
  • Bore tolerance +0.05 /-0.00 mm ensures precise fit

Specifications

No published specifications for this item yet.

Questions about this item

How do I install the clamp-on hub on an 8 mm shaft without damaging the M3 screw threads?

Slide the hub onto the shaft, align the clamp screw with the keyway if present, then tighten the M3 screw to the manufacturer's torque specification; over-tightening strips the threads and reduces clamp force.

When should I replace the aluminum hub or the spider insert under normal operation?

Inspect the curved jaw profile and spider for wear, cracking, or deformation every scheduled maintenance interval; replace the hub if bore tolerance exceeds +0.05/-0.00 mm or if the clamp screw no longer holds the shaft securely.

What is the first limit reached when running continuously at high speed?

The maximum rated speed is 8,000 RPM; exceeding this limit risks hub failure due to centrifugal forces on the aluminum body before other factors become critical.

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